< Home < Developers < Development Support < Documentation

## 66 Serial Manager

Table of Contents | < Previous | Next > | Index

| Title - Palm OS® Programmer's API Reference Part III: Communications 66 Serial Manager Serial Manager Data Structures DeviceInfoType SrmCtlEnum SrmOpenConfigType Serial Manager Constants Port Constants Serial Capabilities Constants Serial Settings Constants Status Constants Line Error Constants Serial Manager Functions SrmClearErr SrmClose SrmControl SrmCustomControl SrmExtOpen SrmExtOpenBackground SrmGetDeviceCount SrmGetDeviceInfo SrmGetStatus SrmOpen SrmOpenBackground SrmPrimeWakeupHandler SrmReceive SrmReceiveCheck SrmReceiveFlush SrmReceiveWait SrmReceiveWindowClose SrmReceiveWindowOpen SrmSend SrmSendCheck SrmSendFlush SrmSendWait SrmSetReceiveBuffer SrmSetWakeupHandler Serial Manager Application-Defined Functions WakeupHandlerProcPtr |  |  |  | This chapter provides reference material for the Serial Manager API: Serial Manager Data Structures Serial Manager Constants Serial Manager Functions Serial Manager Application-Defined Functions The header file SerialMgr.h declares the Serial Manager API. The file SystemResources.h defines some serial port constants. For more information on the Serial Manager, see the chapter "Serial Communication" of the Palm OS Programmer's Companion, vol. II, Communications. ## Serial Manager Data Structures ## DeviceInfoType The DeviceInfoType structure defines information about a serial device. This structure is returned by the SrmGetDeviceInfo function.
    typedef struct DeviceInfoType {
      UInt32 serDevCreator;
      UInt32 serDevFtrInfo;
      UInt32 serDevMaxBaudRate;
      UInt32 serDevHandshakeBaud;
      Char *serDevPortInfoStr;
      UInt8 reserved[8];
    } DeviceInfoType;
    typedef DeviceInfoType *DeviceInfoPtr;
#### Value Descriptions #####
serDevCreator | Four-character creator ID for serial driver.
serDevFtrInfo | Flags defining features of this serial hardware. See Serial Capabilities Constants for a description of these flags.
serDevMaxBaudRate | Maximum baud rate for this device.
serDevHandshakeBaud | Hardware handshaking is recommended for baud rates over this rate.
serDevPortInfoStr | Description of serial hardware device or virtual device.
## SrmCtlEnum The SrmCtlEnum enumerated type specifies a serial control operation. Specify one of these enumerated types for the op parameter to the SrmControl call.
    typedef enum SrmCtlEnum {
      srmCtlFirstReserved = 0,
      srmCtlSetBaudRate,
      srmCtlGetBaudRate,
      srmCtlSetFlags,
      srmCtlGetFlags,
      srmCtlSetCtsTimeout,
      srmCtlGetCtsTimeout,
      srmCtlStartBreak,
      srmCtlStopBreak,
      srmCtlStartLocalLoopback,
      srmCtlStopLocalLoopback,
      srmCtlIrDAEnable,
      srmCtlIrDADisable,
      srmCtlRxEnable,
      srmCtlRxDisable,
      srmCtlEmuSetBlockingHook,
      srmCtlUserDef,
      srmCtlGetOptimalTransmitSize,
      srmCtlSetDTRAsserted,
      srmCtlGetDTRAsserted,
      srmCtlSetYieldPortCallback,
      srmCtlSetYieldPortRefCon,
      srmCtlSystemReserved = 0x7000
      srmCtlCustom = 0x8000,
      srmCtlLAST
    } SrmCtlEnum;
#### Value Descriptions #####
srmCtlSetBaudRate | Sets the current baud rate for the serial hardware.
srmCtlGetBaudRate | Gets the current baud rate for the serial hardware.
srmCtlSetFlags | Sets the current flag settings for the serial hardware. Specify flags from the set described in Serial Settings Constants.
srmCtlGetFlags | Gets the current flag settings for the serial hardware.
srmCtlSetCtsTimeout | Sets the current CTS timeout value for hardware handshaking.
srmCtlGetCtsTimeout | Gets the current CTS timeout value for hardware handshaking.
srmCtlStartBreak | Turn RS-232 break signal on. Caller is responsible for turning this signal on and off and insuring it is on long enough to generate a viable break.
srmCtlStopBreak | Turn RS-232 break signal off.
srmCtlStartLocalLoopback | Start local loopback test.
srmCtlStopLocalLoopback | Stop local loopback test.
srmCtlIrDAEnable | Enable IrDA connection on this serial port. NOTE: You cannot enable an IrDA connection on a VZ processor.
srmCtlIrDADisable | Disable IrDA connection on this serial port.
srmCtlRxEnable | Enable receiver (for IrDA).
srmCtlRxDisable | Disable receiver (for IrDA).
srmCtlEmuSetBlockingHook | Set a blocking hook routine for emulation mode only. Not supported on the actual device.
srmCtlUserDef | This is a user-defined function that third-party hardware developers can use to set or retrieve hardware-specific information from the serial driver. This op code invokes the driver's corresponding control function with its user-defined op code and the parameters are passed directly through to the serial driver. A serial driver that does not handle this function returns a serErrBadParam error.
| The srmCtlUserDef op code is superseded by defining a custom op code if New Serial Manager Feature Set Version 2 is present.
srmCtlGetOptimalTransmitSize | Ask the port for the most efficient buffer size for transmitting data packets. This op code returns an error (buffering not necessary), 0 (buffering requested, but application can choose buffer size), or a number greater than 0 (recommended buffer size).
srmCtlSetDTRAsserted | Enabled or disable the DTR signal. This is not supported by all hardware.
srmCtlGetDTRAsserted | Ask the port whether the DTR signal is enabled or disabled.
srmCtlSetYieldPortCallback | Set the function to be called if the Serial Manager attempts to open another port when this one is open. This op code is for system use only.
srmCtlSetYieldPortRefCon | Data to pass to the yield port callback function. System use only.
srmCtlSystemReserved | Reserves op codes between 0x7000 and 0x8000 for system use.
srmCtlCustom | Reserves op codes greater than 0x8000 for driver-specific use.
#### Compatibility Custom control op codes are only supported if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. ## New SrmOpenConfigType The SrmOpenConfigType structure specifies parameters for opening a serial port. This structure is passed as a parameter to SrmExtOpen.
    typedef struct SrmOpenConfigType {
      UInt32 baud;
      UInt32 function;
      MemPtr drvrDataP;
      UInt16 drvrDataSize;
      UInt32 sysReserved1;
      UInt32 sysReserved2;
    } SrmOpenConfigType;
#### Field Descriptions #####
baud | Baud rate at which to open the connection. Serial drivers that do not require baud rates ignore this field.
function | The reason why the port was opened. Specify the creator ID of the application that is opening the port or one of the following values: #####
serFncUndefined | Undefined function. This is the default value for this field.
#####
serFncPPPSession | The connection is to be used for the PPP interface.
#####
serFncSLIPSession | The connection is to be used for the SLIP session.
#####
serFncDebugger | The connection is to be used for a debugging session.
#####
serFncHotSync | The connection is to be used for a HotSync operation.
#####
serFncConsole | The connection is to the debugging console.
#####
serFncTelephony | The connection is to the telephony library.
| The function field is used by protocols such as USB and Bluetooth that perform different setup tasks based on which type of application is using them. RS-232 drivers ignore this parameter.
drvrDataP | Pointer to a driver-specific data block.
drvrDataSize | The size of the data block pointed to by drvrDataP.
sysReserved1 | Reserved for future use.
sysReserved2 | Reserved for future use.
#### Compatibility This structure is only defined if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. ## Serial Manager Constants ## Port Constants When you specify the port to open in the SrmOpen, SrmOpenBackground, SrmExtOpen, or SrmExtOpenBackground call, you can use either a logical port constant, physical port constant, or a virtual port constant, but it is highly recommended that you use a logical port constant wherever possible. #### Logical Serial Port Constants These constants specify the logical port names. #####
Constant | Value | Description
--- | --- | ---
serPortLocalHotSync | 0x8000 | The physical HotSync port. The Serial Manager automatically detects whether this port is USB or RS-232.
serPortCradlePort | 0x8000 | Cradle port. The Serial Manager automatically detects whether this port is USB or RS-232. Most applications should specify this as the port.
serPortIrPort | 0x8001 | The IR port. This is a raw IrDA port with no protocol support.
serPortConsolePort | 0x8002 | The debug console port, either USB or RS-232. USB is preferred where both are available.
serPortCradleRS232Port | 0x8003 | Port for the RS-232 cradle. Specify this port if you want to ensure that your application uses RS-232 communications only.
serPortCradleUSBPort | 0x8004 | Port for the USB cradle. Specify this port if you want to ensure that your application uses USB communications only.
#### Compatibility USB ports are only supported if New Serial Manager Feature Set Version 2 is present. #### Physical Serial Port Constants The physical port constants specify 4-character constants that reference the physical hardware of the device. Doing so is not recommended because the hardware they reference may not exist on a particular device. #####
Physical port | Value | Description
--- | --- | ---
sysFileCUart328 | 'u328' | Cradle port using the 68328 UART. This port can be switched between RS232 and IrDA mode using the SrmControl call.
sysFileCUart328EZ | 'u8EZ' | Cradle port using the 68328EZ UART. This port can also be switched between RS232 and IrDA mode.
sysFileCUart650 | 'u650' | Specifies the IR port on the upgrade card for Palm Personal or Palm Professional devices. This gives you a raw IR port like calling SrmControl does, but it only exists on devices that have the upgrade card.
#### Virtual Serial Port Constants The virtual port constants specify 4-character constants that identify virtual ports, simulating a hardware interface. Virtual ports are not tied to specific hardware. #####
Physical port | Value | Description
--- | --- | ---
sysFileCVirtIrComm | 'ircm' | A virtual serial cable over an IrDA link using the IRComm protocol. It can only be used to talk to another IRComm device.
sysFileCVirtRfComm | 'rfcm' | RFCOMM (Bluetooth) virtual port plug-in.
sysFileCBtConnectPanelHelper | 'btcp' | Bluetooth Connection Panel helper application.
#### Compatibility All virtual port constants other than sysFileCVirtIrComm are only defined if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. ## Serial Capabilities Constants The serial capabilities constant flags describe serial hardware capabilities. These flags are set in the serDevFtrInfo field of the DeviceInfoType structure. #####
Constant | Value | Description
--- | --- | ---
serDevCradlePort | 0x00000001 | Serial hardware controls RS-232 serial from cradle connector of Palm device.
serDevRS232Serial | 0x00000002 | Serial hardware has RS-232 line drivers.
serDevIRDACapable | 0x00000004 | Serial hardware has IR line drivers and generates IrDA mode serial signals.
serDevModemPort | 0x00000008 | Serial hardware drives modem connection.
serDevCncMgrVisible | 0x00000010 | Serial device port name string is to be displayed in the Connection panel.
serDevConsolePort | 0x00000020 | Serial device is the default console port.
serDevUSBCapable | 0x00000040 | Serial hardware controls USB serial from cradle connector of Palm device.
#### Compatibility USB ports are only supported if New Serial Manager Feature Set Version 2 is present. ## Serial Settings Constants The serial settings constants identify bit flags that correspond to various serial hardware settings. Use SrmControl with the op code srmCtlSetFlags to control which settings are used. #####
Constant | Value | Description
--- | --- | ---
srmSettingsFlagStopBitsM | 0x00000001 | Mask for stop bits field
srmSettingsFlagStopBits1 | 0x00000000 | 1 stop bit (default)
srmSettingsFlagStopBits2 | 0x00000001 | 2 stop bits
srmSettingsFlagParityOnM | 0x00000002 | Mask for parity on
srmSettingsFlagParityEvenM | 0x00000004 | Mask for parity even
srmSettingsFlagXonXoffM | 0x00000008 | Mask for Xon/Xoff flow control (not implemented)
srmSettingsFlagRTSAutoM | 0x00000010 | Mask for RTS receive flow control. This is the default.
srmSettingsFlagCTSAutoM | 0x00000020 | Mask for CTS transmit flow control
srmSettingsFlagBitsPerCharM | 0x000000C0 | Mask for bits per character
srmSettingsFlagBitsPerChar5 | 0x00000000 | 5 bits per character
srmSettingsFlagBitsPerChar6 | 0x00000040 | 6 bits per character
srmSettingsFlagBitsPerChar7 | 0x00000080 | 7 bits per character
srmSettingsFlagBitsPerChar8 | 0x000000C0 | 8 bits per character (default)
srmSettingsFlagFlowControlIn | 0x00000100 | Protect the receive buffer from software overruns. When this flag and srmSettingsFlagRTSAutoM are set, which is the default case, it causes the Serial Manager to assert RTS to prevent the transmitting device from continuing to send data when the receive buffer is full. Once the application receives data from the buffer, RTS is de-asserted to allow data reception to resume.
|  | Note that this feature effectively prevents software overrun line errors but may also cause CTS timeouts on the transmitting device if the RTS line is asserted longer than the defined CTS timeout value.
srmSettingsFlagRTSInactive | 0x00000200 | If this flag is set and srmSettingsFlagRTSAutoM is not set, RTS is held in the inactive (flow off) state forever.
## Status Constants The status constants identify bit flags that correspond to the status of serial signals. They can be returned by the SrmGetStatus function. #####
Constant | Value | Description
--- | --- | ---
srmStatusCtsOn | 0x00000001 | CTS line is active.
srmStatusRtsOn | 0x00000002 | RTS line is active.
srmStatusDsrOn | 0x00000004 | DSR line is active.
srmStatusBreakSigOn | 0x00000008 | Break signal is active.
## Line Error Constants The line error constants identify bit flags that correspond to the line errors that may occur on the port. They can be returned by the SrmGetStatus function. #####
Constant | Value | Description
--- | --- | ---
serLineErrorParity | 0x0001 | Parity error
serLineErrorHWOverrun | 0x0002 | Hardware overrun
serLineErrorFraming | 0x0004 | Framing error
serLineErrorBreak | 0x0008 | Break signal asserted
serLineErrorHShake | 0x0010 | Line handshake error
serLineErrorSWOverrun | 0x0020 | Software overrun
serLineErrorCarrierLost | 0x0040 | Carrier detect signal dropped
## Serial Manager Functions ## SrmClearErr #### Purpose Clears the port of any line errors. #### Prototype Err SrmClearErr (UInt16 portId) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrNotSupported | The port is not the foreground port.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. ## SrmClose #### Purpose Closes a serial port and makes it available to other applications, regardless of whether the port is a foreground or background port. #### Prototype Err SrmClose (UInt16 portId) #### Parameters #####
-> portId | Port ID for port to be closed.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The serial port is not open.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments If a foreground port is being closed and a background port exists, the background will have access to the port as long as another foreground port is not opened. If a foreground port is being closed and a yielded port exists, the yielded port will have access to the port as long as it does not yield to the opening of another foreground port. If there are both a yielded port and a background port for the foreground port being closed, the yielded port takes precedence over the background port. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmOpen, SrmOpenBackground ## SrmControl #### Purpose Performs a serial control function. #### Prototype Err SrmControl (UInt16 portId, UInt16 op, void *valueP, UInt16 *valueLenP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> op | Control operation to perform. Specify one of the SrmCtlEnum enumerated types.
#####
<-> valueP | Pointer to a value to use for the operation. See Comments for details.
#####
<-> valueLenP | Pointer to the size of *valueP. See Comments for details.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadParam | An invalid op code was specified.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The serial port is not open.
#####
serErrNoDevicesAvail | No serial devices could be found.
#####
serErrNotSupported | The specified op code is not supported in the current configuration.
#### Comments Table 66.1 shows what to pass for the valueP and valueLenP parameters for each of the operation codes. Control codes not listed do not use these parameters. See SrmCtlEnum for a complete list of control codes. #####
Table 66.1 SrmControl Parameters
Operation Code | Parameters
--- | ---
srmCtlSetBaudRate | -> valueP = Pointer to Int32 (baud rate) -> valueLenP = Pointer to sizeof(Int32)
srmCtlGetBaudRate | <- valueP = Pointer to Int32 (baud rate) <- valueLenP = Pointer to Int16
srmCtlSetFlags | -> valueP = Pointer to Uint32 (bitfield; see Serial Settings Constants) -> valueLenP = Pointer to sizeof(UInt32)
srmCtlGetFlags | <- valueP = Pointer to UInt32 (bitfield) <- valueLenP = Pointer to Int16
srmCtlSetCtsTimeout | -> valueP = Pointer to Int32 (timeout value) -> valueLenP = Pointer to sizeof(Int32)
srmCtlGetCtsTimeout | <- valueP = Pointer to Int32 (timeout value) <- valueLenP = Pointer to Int16
srmCtlUserDef | <-> valueP = Pointer passed to the serial or virtual driver <-> valueLenP = Pointer to sizeof(Int32) For a serial driver, these pointers are passed to the driver's control function and they contain that functions return values (if any) upon return.
srmCtlGetOptimalTransmitSize | <- valueP = Pointer to Int32 <- valueLenP = Pointer to sizeof(Int32) If an error is returned by SrmControl, no buffering should be done. If valueP points to zero, buffering is requested, but the transmitting application cannot determine the buffer size. If valueP points to a number > 0, then try to send data in blocks of this number of bytes, as this is the most efficient block size for this particular device.
srmCtlSetDTRAsserted | -> valueP = Pointer to Boolean indicating whether to enable or disable DTR. -> valueLenP = Pointer to sizeof(Boolean)
srmCtlGetDTRAsserted | <- valueP = Pointer to Boolean indicating whether DTR is enabled. <- valueLenP = Pointer to Int16
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmCustomControl ## New SrmCustomControl #### Purpose Performs a custom serial control function. #### Prototype Err SrmCustomControl (UInt16 portId, UInt16 opCode, UInt32 creator, void *valueP, UInt16 *valueLenP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> opCode | Control operation to perform. The op code must be greater than srmCtlCustom.
#####
-> creator | Creator ID of the driver that defines the op code. The combination of creator ID and op code uniquely identifies the operation to be performed.
#####
<-> valueP | Pointer to a value to use for the operation.
#####
<-> valueLenP | Pointer to the size of *valueP.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The serial port is not open.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments This function is a mechanism for a virtual driver to create control codes specific to that driver, allowing for the support of new technologies that have interfaces through the Serial Manager. This function simply forwards the opCode and any valueP parameter to the virtual driver for the port. The virtual driver may return its own error code if the opCode or the input in valueP is invalid. #### Compatibility Implemented only if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. #### See Also SrmControl ## New SrmExtOpen #### Purpose Opens a foreground port connection with the specified configuration. #### Prototype Err SrmExtOpen (UInt32 port, SrmOpenConfigType *configP, UInt16 configSize, UInt16 *newPortIdP) #### Parameters #####
-> port | The four-character port name (such as 'ircm' or 'u328') or logical port number to be opened. (See Port Constants.)
#####
-> configP | Pointer to the configuration structure specifying the serial port's properties. See SrmOpenConfigType.
#####
-> configSize | The size of the configuration structure pointed to by configP.
#####
<- newPortIdP | Contains the port ID to be passed to other Serial Manager functions.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | The port parameter does not specify a valid port.
#####
serErrBadParam | The configP parameter is NULL.
#####
serErrAlreadyOpen | The Serial Manager already has a port open.
#####
memErrNotEnoughSpace | There was not enough memory available to open the port.
#### Comments Do not keep the port open any longer than necessary. An open serial port consumes more energy from the device's batteries. The values specified in the configP parameter depend on the type of connection being made. For RS-232 connections, you specify the baud rate but not a purpose. For USB connections, you specify a purpose but not a baud rate. A newly opened port has its line errors cleared, the default CTS timeout set (specified by the constant srmDefaultCTSTimeout), a 512-byte receive queue allocated, 1 stop bit, 8 bits per character, RTS enabled, and flow control enabled. To increase the receive queue size, use SrmSetReceiveBuffer. To change the other serial port settings, use SrmControl. #### Compatibility Implemented only if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. The SrmExtOpen function replaces the SrmOpen function. #### See Also SrmOpen, SrmExtOpenBackground ## New SrmExtOpenBackground #### Purpose Opens a port with the specified configuration in the background. Background ports relinquish control when another task opens the port with the SrmOpen or SrmExtOpen call. #### Prototype Err SrmExtOpenBackground (UInt32 port, SrmOpenConfigType *configP, UInt16 configSize, UInt16 *newPortIdP) #### Parameters #####
-> port | Physical or logical port number to be opened. See Port Constants for more information.
#####
-> configP | Pointer to the configuration structure specifying the serial port's properties. See SrmOpenConfigType.
#####
-> configSize | The size of the configuration structure pointed to by configP.
#####
<- newPortIdP | Contains the port ID to be passed to other Serial Manager functions.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrAlreadyOpen | This port already has an installed background owner.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotSupported | This type of port cannot be opened in the background.
#####
serErrBadParam | The configP parameter is NULL.
#####
memErrNotEnoughSpace | There was not enough memory available to open the port.
#### Comments This function is provided to support tasks that want to use a serial device to receive data only when no other task is using the port. If a background port is forced to surrender control of the hardware as a result of another task opening a foreground connection, all buffers for the background port are flushed. After this active task closes the port, active control of the port is returned to the background task. Only one task can have background ownership of the port. Note that background ports have limited functionality: they can only receive data and notify owning clients of what data has been received. The values specified in the configP parameter depend on the type of connection being made. For RS-232 connections, you specify the baud rate but not a purpose. For USB connections, you specify a purpose but not a baud rate. #### Compatibility Implemented only if both New Serial Manager Feature Set Version 2 and 4.0 New Feature Set are present. The SrmExtOpenBackground function replaces the SrmOpenBackground function. #### See Also SrmOpen, SrmExtOpen ## SrmGetDeviceCount #### Purpose Returns the number of available serial devices. #### Prototype Err SrmGetDeviceCount (UInt16 *numOfDevicesP) #### Parameters #####
<- numOfDevicesP | Pointer to address where the number of serial devices is returned.
#### Result #####
errNone | No error.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmGetDeviceInfo ## SrmGetDeviceInfo #### Purpose Returns information about a serial device. #### Prototype Err SrmGetDeviceInfo (UInt32 deviceID, DeviceInfoType *deviceInfoP) #### Parameters #####
-> deviceID | ID of serial device to get information for. You can pass a zero-based index (0, 1, 2, ...), a valid port ID returned from SrmOpen or SrmExtOpen, or a 4-character port name (such as 'u328', 'u650', or 'ircm'). See Port Constants.
#####
<- deviceInfoP | Pointer to a DeviceInfoType structure where information about the device is returned.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNoDevicesAvail | The Serial Manager cannot find any serial devices.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmGetDeviceCount ## SrmGetStatus #### Purpose Returns status information about the serial hardware. #### Prototype Err SrmGetStatus (UInt16 portId, UInt32 *statusFieldP, UInt16 *lineErrsP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
<- statusFieldP | Pointer to address where hardware status information for the port is returned. This is a 32-bit field using the flags described in Status Constants.
#####
<- lineErrsP | Pointer to address where the number of line errors for the port is returned. The line error flags are described in Line Error Constants.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotSupported | The port is a yielded port.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments Typically, SrmGetStatus is called to retrieve the line errors for the port if some of the send and receive functions return a serErrLineErr error code. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. ## SrmOpen #### Purpose Opens a foreground port connection with the specified port name or logical port number. #### Prototype Err SrmOpen (UInt32 port, UInt32 baud, UInt16 *newPortIdP) #### Parameters #####
-> port | The four-character port name or logical port number to be opened. See Port Constants for more information.
#####
-> baud | Initial baud rate of port.
#####
<- newPortIdP | Contains the port ID to be passed to other Serial Manager functions.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrAlreadyOpen | This port already has an installed foreground owner.
#####
serErrBadPort | This port doesn't exist.
#####
memErrNotEnoughSpace | There was not enough memory available to open the port.
#### Comments Only one application or task may have access to a particular serial port at any time. Do not keep the port open any longer than necessary. An open serial port consumes more energy from the device's batteries. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. If New Serial Manager Feature Set Version 2 is present, the SrmOpen function is replaced by SrmExtOpen. SrmOpen is supported for backward compatibility. #### See Also SrmOpenBackground ## SrmOpenBackground #### Purpose Allows a task to open, initialize, and use the port, but always relinquishes control of the port when another task opens the port with the SrmOpen call. #### Prototype Err SrmOpenBackground (UInt32 port, UInt32 baud, UInt16 *newPortIdP) #### Parameters #####
-> port | The four-character port name or logical port number to be opened. See Port Constants for more information.
#####
-> baud | Initial baud rate of port.
#####
<- newPortIdP | Contains the port ID to be passed to other Serial Manager functions.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrAlreadyOpen | This port already has an installed background owner.
#####
serErrBadPort | This port doesn't exist.
#####
memErrNotEnoughSpace | There was not enough memory available to open the port.
#### Comments This function is provided to support tasks that want to use a serial device to receive data only when no other task is using the port. If a background port is forced to surrender control of the hardware as a result of another task opening a foreground connection, all buffers for the background port are flushed. After this active task closes the port, active control of the port is returned to the background task. Only one task can have background ownership of the port. Note that background ports have limited functionality: they can only receive data and notify owning clients of what data has been received. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. If New Serial Manager Feature Set Version 2 is present, the SrmOpenBackground function is replaced by SrmExtOpenBackground. SrmOpenBackground is supported for backward compatibility. #### See Also SrmOpen ## SrmPrimeWakeupHandler #### Purpose Sets the number of received bytes that triggers a call to the wakeup handler function. #### Prototype Err SrmPrimeWakeupHandler (UInt16 portId, UInt16 minBytes) #### Parameters #####
-> portId | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> minBytes | Number of bytes that must be received before wakeup handler is called. Typically, this is set to 1.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments This function primes a wakeup handler installed by SrmSetWakeupHandler. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmSetWakeupHandler, WakeupHandlerProcPtr ## SrmReceive #### Purpose Receives a specified number of bytes. #### Prototype UInt32 SrmReceive (UInt16 portId, void *rcvBufP, UInt32 count, Int32 timeout, Err *errP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
<- rcvBufP | Pointer to buffer where received data is to be returned.
#####
-> count | Length of data buffer (in bytes). This specifies the number of bytes to receive.
#####
-> timeout | The amount of time (in ticks) that the Serial Manager waits to receive the requested block of data. At the end of the timeout, data received up to that time is returned.
#####
<- errP | Error code.
#### Result Number of bytes of data actually received. #### Comments The following error codes can be returned in errP: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrTimeOut | Unable to receive data within the specified timeout period.
#####
serErrConfigurationFailed | The port needs time to configure, and the configuration has failed.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrConfigurationFailed | The port could not configure itself.
#####
serErrLineErr | A line error occurred during the receipt of data. Use SrmGetStatus to obtain the exact line error.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceiveCheck, SrmReceiveFlush, SrmReceiveWait ## SrmReceiveCheck #### Purpose Checks the receive FIFO and returns the number of bytes in the serial receive queue. #### Prototype Err SrmReceiveCheck (UInt16 portId, UInt32 *numBytesP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
<- numBytesP | Number of bytes in the receive queue.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrLineErr | A line error has occurred. Use SrmGetStatus to obtain the exact line error.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceive, SrmReceiveFlush, SrmReceiveWait ## SrmReceiveFlush #### Purpose Flushes the receive FIFOs. #### Prototype Err SrmReceiveFlush (UInt16 portId, Int32 timeout) #### Parameters #####
-> portId | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> timeout | Timeout value, in ticks.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments The timeout value forces this function to wait a period of ticks after flushing the port to see if more data shows up to be flushed. If more data arrives within the timeout period, the port is flushed again and the timeout counter is reset and waits again. The function only exits after no more bytes are received by the port for the full timeout period since the last flush of the port. To avoid this waiting behavior, specify 0 for the timeout period. Any errors on the line are cleared before this function returns. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceive, SrmReceiveCheck, SrmReceiveWait ## SrmReceiveWait #### Purpose Waits until some number of bytes of data have arrived into the serial receive queue, then returns. #### Prototype Err SrmReceiveWait (UInt16 portId, UInt32 bytes, Int32 timeout) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> bytes | Number of bytes to wait for.
#####
-> timeout | Timeout value, in ticks.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrTimeOut | Unable to receive data within the specified timeout period.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrBadParam | The bytes parameter exceeds the size of the receive queue. Use SrmSetReceiveBuffer to increase the size of the receive queue.
#####
serErrLineErr | A line error occurred during the receipt of data. Use SrmGetStatus to obtain the exact line error.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments If this function returns no error, the application can either check the number of bytes currently in the receive queue (using SrmReceiveCheck) or it can just specify a buffer and receive the data by calling SrmReceive. Do not call SerReceiveWait from within a wakeup handler. If you do, the serErrTimeOut error is returned. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceive, SrmReceiveCheck, SrmReceiveFlush ## SrmReceiveWindowClose #### Purpose Closes direct access to the Serial Manager's receive queue. #### Prototype Err SrmReceiveWindowClose (UInt16 portId, UInt32 bytesPulled) #### Parameters #####
-> portId | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> bytesPulled | Number of bytes the application read from the receive queue.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments Call this function when the application has read as many bytes as it needs out of the receive queue or it has read all the available bytes. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceiveWindowOpen ## SrmReceiveWindowOpen #### Purpose Provides direct access to the Serial Manager's receive queue. #### Prototype Err SrmReceiveWindowOpen (UInt16 portId, UInt8 **bufPP, UInt32 *sizeP) #### Parameters #####
-> portId | Port ID returned from SrmOpen or SrmExtOpen.
#####
<- bufPP | Pointer to a pointer to the receive buffer.
#####
<- sizeP | Available bytes in buffer.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrLineErr | The data in the queue contains line errors.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments This function lets applications directly access the Serial Manager's receive queue to eliminate buffer copying by the Serial Manager. This access is a "back door" route to the received data. After retrieving data from the buffer, the application must call SrmReceiveWindowClose. Applications that want to empty the receive buffer entirely should call the SrmReceiveWindowOpen and SrmReceiveWindowClose functions repeatedly until the buffer size returned is 0. IMPORTANT: Once an application calls SrmReceiveWindowOpen, it should not attempt to receive data via the normal method of calling SrmReceive or SrmReceiveWait, as these functions interfere with direct access to the receive queue. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmReceiveWindowClose ## SrmSend #### Purpose Sends a block of data out the specified port. #### Prototype UInt32 SrmSend (UInt16 portId, const void *bufP, UInt32 count, Err *errP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> bufp | Pointer to data to send.
#####
-> count | Length of data buffer, in bytes.
#####
<- errP | Error code. See the Comments section for details.
#### Result Number of bytes of data actually sent. #### Comments When SrmSend returns, you should check the value returned in the errP parameter. If errNone, then the entire data buffer was sent. If not errNone, then the result equals the number of bytes sent before the error occurred. The possible error values are: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrTimeOut | Unable to send data within the specified CTS timeout period.
#####
serErrNoDevicesAvail | No serial devices could be found.
#####
serErrConfigurationFailed | The port configuration has failed.
#####
serErrNotSupported | The specified port is not the foreground port.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmSendCheck, SrmSendFlush, SrmSendWait ## SrmSendCheck #### Purpose Checks the transmit FIFO and returns the number of bytes left to be sent. #### Prototype Err SrmSendCheck (UInt16 portId, UInt32 *numBytesP) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
<- numBytesP | Number of bytes left in the FIFO queue.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNotSupported | This feature not supported by the hardware.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments Not all serial devices support this feature. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmSend, SrmSendFlush, SrmSendWait ## SrmSendFlush #### Purpose Flushes the transmit FIFO. #### Prototype Err SrmSendFlush (UInt16 portId) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmSend, SrmSendCheck, SrmSendWait ## SrmSendWait #### Purpose Waits until all previous data has been sent from the transmit FIFO, then returns. #### Prototype Err SrmSendWait (UInt16 portId) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrTimeOut | Unable to send data within the CTS timeout period.
#####
serErrNotSupported | The port is not the foreground port.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments Consider calling this function if your software needs to detect when all data has been transmitted by SrmSend. The SrmSend function blocks until all data has been transmitted or a timeout occurs. A subsequent call to SrmSendWait blocks until all data queued up for transmission has been transmitted or until another CTS timeout occurs (if CTS handshaking is enabled). #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmSend, SrmSendCheck, SrmSendFlush ## SrmSetReceiveBuffer #### Purpose Installs a new buffer into the Serial Manager's receive queue. #### Prototype Err SrmSetReceiveBuffer (UInt16 portId, void *bufP, UInt16 bufSize) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> bufP | Pointer to new receive buffer. Ignored if bufSize is NULL.
#####
-> bufSize | Size of new receive buffer in bytes. To remove this buffer and allocate a new default buffer (512 bytes), specify NULL.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | This port is not open.
#####
memErrNotEnoughSpace | Not enough memory to allocate default buffer.
#####
serErrNoDevicesAvail | No serial devices could be found.
##### #### Comments The buffer that you pass to this function must remain allocated while you have the serial port open. Before you close the serial port, you must restore the default queue by calling SrmSetReceiveBuffer with NULL as the bufP and bufSize arguments. IMPORTANT: Applications must install the default buffer before closing the port (or disposing of the new receive queue). #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. ## SrmSetWakeupHandler #### Purpose Installs a wakeup handler. #### Prototype Err SrmSetWakeupHandler (UInt16 portId, WakeupHandlerProcPtr procP, UInt32 refCon) #### Parameters #####
-> portID | Port ID returned from SrmOpen or SrmExtOpen.
#####
-> procP | Pointer to a WakeupHandlerProcPtr function. Specify NULL to remove a handler.
#####
-> refCon | User-defined data that is passed to the wakeup handler function. This can be a pointer or not.
#### Result This function returns the following error codes: #####
errNone | No error.
#####
serErrBadPort | This port doesn't exist.
#####
serErrNotOpen | The port is not open.
#####
serErrNoDevicesAvail | No serial devices could be found.
#### Comments The wakeup handler is a function in your application that you want to be called whenever there is data ready to be received on the specified port. The wakeup handler function will not become active until it is primed with a number of bytes that is greater than 0, by the SrmPrimeWakeupHandler function. Every time a wakeup handler is called, it must be re-primed (using SrmPrimeWakeupHandler) in order to be called again. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmPrimeWakeupHandler, WakeupHandlerProcPtr ## Serial Manager Application-Defined Functions ## WakeupHandlerProcPtr #### Purpose Called after some number of bytes are received by the Serial Manager's interrupt function. #### Prototype void (*WakeupHandlerProcPtr)(UInt32 refCon) #### Parameters #####
->refCon | User-defined data passed from the SrmSetWakeupHandler function.
#### Result Returns nothing. #### Comments This handler function is installed by calling SrmSetWakeupHandler. The number of bytes after which it is called is specified by SrmPrimeWakeupHandler. IMPORTANT: Because wakeup handlers are called during interrupt time, they cannot call any Palm OS® system functions, including SrmReceive, that may block the system in any way. Wakeup handlers should also be very short so as to reduce interrupt latency. Two common implementations of wakeup handlers include: Calling EvtWakeup, which causes any pending EvtGetEvent call to return and then sends a nilEvent to the current application. Using SrmReceiveWindowOpen and SrmReceiveWindowClose to gain direct access to the receive queue without blocking. #### Compatibility Implemented only if New Serial Manager Feature Set Version 1 is present. #### See Also SrmPrimeWakeupHandler, SrmSetWakeupHandler |