Received-Message-Lost Register (Canrml); Remote-Frame-Pending Register (Canrfp); Received-Message-Lost Register (Canrml) Field Descriptions; Remote-Frame-Pending Register (Canrfp) Field Descriptions - Texas Instruments TMS320 2833 Series Reference Manual

eCAN Registers

13.8.8 Received-Message-Lost Register (CANRML)

An RML[n] bit is set if an old message has been overwritten by a new one in mailbox n. These bits can
only be reset by the CPU, and set by the internal logic. The bits can be cleared by a write access to the
CANRMP register with a 1 at the corresponding bit location. If the CPU tries to reset a bit and the CAN
tries to set the bit at the same time, the bit is set. The CANRML register is not changed if the OPC[n]
(OPC.31-0) bit is set.
If one or more of the bits in the CANRML register are set, the RMLIF (GIF0.11/ GIF1.11) bit is also set.
This can initiate an interrupt if the RMLIM (GIM.11) bit is set.
31
LEGEND: R = Read; -n = value after reset
Table 13-16. Received-Message-Lost Register (CANRML) Field Descriptions
Bit Field
31:0 RML[31:0]

13.8.9 Remote-Frame-Pending Register (CANRFP)

Whenever a remote frame request is received by the CAN module, the corresponding bit RFP[n] in the
remote frame pending register is set. If a remote frame is stored in a receive mailbox (AAM=0,
CANMD=1), the RFPn bit will not be set.
To prevent an auto-answer mailbox from replying to a remote frame request, the CPU has to clear the
RFP[n] flag and the TRS[n] bit by setting the corresponding transmission request reset bit TRR[n]. The
AAM bit can also be cleared by the CPU to stop the module from sending the message.
If the CPU tries to reset a bit and the CAN module tries to set the bit at the same time, the bit is not set.
The CPU cannot interrupt an ongoing transfer.
31
LEGEND: RC = Read/Clear; -n = value after reset
Table 13-17. Remote-Frame-Pending Register (CANRFP) Field Descriptions
Bit Field
31:0 RFP.31:0
806
Controller Area Network (CAN)
Figure 13-17. Received-Message-Lost Register (CANRML)
Value Description
Received-message-lost bits
1 An old unread message has been overwritten by a new one in that mailbox.
0 No message was lost.
Note: The RMLn bit is cleared by clearing the set RMPn bit.
Figure 13-18. Remote-Frame-Pending Register (CANRFP)
Value Description
Remote-frame-pending register.
For a receive mailbox, RFPn is not set if a remote frame is received and TRSn is not affected.
For a transmit mailbox, RFPn is set if a remote frame is received and TRSn is set if AAM of the
mailbox is 1. The ID of the mailbox must match the remote frame ID.
1 A remote-frame request was received by the module.
0 No remote-frame request was received. The register is cleared by the CPU.
Copyright © 2020, Texas Instruments Incorporated
RML[31:0]
R-0
RFP.31:0
RC-0
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0
SPRUI07 – March 2020
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