Figure 18-43: Transmission Via Interrupt (Using Cntgpt Register) - NEC V850E/PH2 User Manual

Figure 18-43: Transmission via interrupt (using CnTGPT register)

Cautions: 1. The TRQ bit should be set after the RDY bit is set.
2. The RDY bit and TRQ bit should not be set at the same time.
Remarks: 1. Also check the MBON flag at the beginning and at the end of the interrupt routine, in
order to check the access to the message buffers as well as TX history list registers, in
case a pending sleep mode had been executed. If MBON is detected to be cleared at
any check, the actions and results of the processing have to be discarded and pro-
cessed again, after MBON is set again.
It is recommended to cancel any sleep mode requests, before processing TX interrupts.
2. If TOVF was set once, the transmit history list is inconsistent. Consider to scan all con-
figured transmit buffers for completed transmissions.
848
Chapter 18 AFCAN Controller
Transmit completion Transmit completion Transmit completion
interrupt processing interrupt processing interrupt processing
Read CnTGPT register Read CnTGPT register
TOVF = 1? TOVF = 1?
No No
Clear TOVF bit Clear TOVF bit
Clear RDY bit Clear RDY bit
Data frame Data frame
Data frame or remote frame? Data frame or remote frame?
Set CnMDATAxm register Set CnMDATAxm register
Set CnMDLCm register Set CnMDLCm register
Clear RTR bit of CnMCONFm Clear RTR bit of CnMCONFm
register register
Set CnMIDLm and CnMIDHm Set CnMIDLm and CnMIDHm
registers registers
User's Manual U16580EE3V1UD00
START START
Yes Yes
No No
RDY = 0? RDY = 0?
Yes Yes
Remote frame Remote frame
Set CnMDLCm register Set CnMDLCm register
Set RTR bit of CnMCONFm Set RTR bit of CnMCONFm
register register
Set CnMIDLm and CnMIDHm Set CnMIDLm and CnMIDHm
registers registers
Set RDY bit Set RDY bit
Set TRQ bit Set TRQ bit
No No
THPM = 1? THPM = 1?
Yes Yes
END END