Mikroelektronika MIKROE-724 データシート

252

mikoBasic PRO for dsPIC30/33 and PIC24

MikroElektronika

CANxSetMask

Prototype

sub procedure CANxSetMask(dim CAN_MASK as word, dim val as longint, dim

CAN_CONFIG_FLAGS as word)

Description Function sets mask for advanced filtering of messages. Given

value

is bit adjusted to appropriate

buffer mask registers.

Parameters -

CAN_MASK

: CAN module mask number. Valid values:

CAN_MASK

constants. See CAN_MASK

constants.

val

: mask register value. This value is bit-adjusted to appropriate buffer mask registers

CAN_CONFIG_FLAGS

: selects type of message to filter. Valid values:

- _CAN_CONFIG_ALL_VALID_MSG,

- _CAN_CONFIG_MATCH_MSG_TYPE & _CAN_CONFIG_STD_MSG,

- _CAN_CONFIG_MATCH_MSG_TYPE & _CAN_CONFIG_XTD_MSG.

See CAN_CONFIG_FLAGS constants.

Returns

Nothing.

Requires

MCU with the CAN module.

MCU must be connected to the CAN transceiver (MCP2551 or similar) which is connected to the CAN

bus.

CAN must be in Config mode, otherwise the function will be ignored. See CANxSetOperationMode.

Example

‘ set appropriate filter mask and message type value

CAN1SetOperationMode(_CAN_MODE_CONFIG,0xFF) ‘ set CONFIGURATION mode (CAN1

module must be in config mode for mask settings)

‘ Set all B1 mask bits to 1 (all filtered bits are relevant)

‘ Note that -1 is just a cheaper way to write 0xFFFFFFFF.

‘ Complement will do the trick and fill it up with ones.

CAN1SetMask(_CAN_MASK_B1, -1, _CAN_CONFIG_MATCH_MSG_TYPE and _CAN_CONFIG_

XTD_MSG)

Notes

- CAN library routine require you to specify the module you want to use. To use the desired CAN

module, simply change the letter

x in the routine prototype for a number from 1 to 2.

- Number of CAN modules per MCU differs from chip to chip. Please, read the appropriate datasheet

before utilizing this library.