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Ver.0.10
13.6.2 Data Frame Receive Operation
The following describes data frame receive operation. The operations described below are
automatically performed in hardware.
(1) Acceptance filtering
When the CAN module finished receiving data, it starts searching for the slot that satisfies
conditions for receiving the received message sequentially from slot 0 (up to slot 15). The
following shows receive conditions for slots that have been set for data frame reception.
[Conditions]
• The receive frame is a data frame.
• The receive ID and the slot ID are identical, assuming the ID Mask Register bits set to 0 are
"Don't care bits."
• The standard and extended frame types are the same.
Note: In BasicCAN mode, slots 14 and 15 while being set for data frame reception can also
receive remote frames.
(2) When receive conditions are met
When receive conditions in (1) above are met, the CAN module sets the CAN Message Slot
Control Register's TRSTAT (Transmit/Receive Status) and TRFIN (Transmit/Receive Finished)
bits to 1 while at the same time writing the received data to the message slot. If the TRFIN
(Transmit/Receive Finished) bit is already 1, the CAN module also sets the ML (Message Lost)
bit to 1, indicating that the message slot has been overwritten. The message slot has its ID field
and DLC field both overwritten and an indeterminate value written in its unused area (e.g.,
extended ID field for standard frame reception and an unused data field).
Furthermore, a time stamp count value at the time the message was received is written to the
CAN Message Slot Time Stamp (C0MSLnTSP) along with the received data. When the CAN
module finished writing to the message slot, it sets the CAN Slot Interrupt Status bit to 1. If the
interrupt for the slot has been enabled, an interrupt request is generated, and the slot goes to a
wait state for the next reception.
(3) When receive conditions are not met
The received frame is discarded, and the CAN module goes to the next transmit/receive
operation without writing to the message slot.
CAN MODULE
13.6 Receiving Data Frames
Summary of Contents for M32170F3VFP
Page 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Page 56: ...2 2 14 Ver 0 10 This is a blank page ...
Page 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Page 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Page 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Page 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Page 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Page 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Page 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Page 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...