SH7261 Datasheet, PDF (849/1348 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7260 Series

Section 19 Controller Area Network (RCAN-ET) [R5S72611] [R5S72613]
19.3.2 Message Control Field
STDID[10:0]: These bits set the identifier (standard identifier) of data frames and remote frames.
EXTID[17:0]: These bits set the identifier (extended identifier) of data frames and remote frames.
RTR (Remote Transmission Request bit): Used to distinguish between data frames and remote
frames. This bit is overwritten by received CAN Frames depending on Data Frames or Remote
Frames.
Important: Please note that, when ATX bit is set with the setting MBC = B'001, the RTR bit will
never be set. When a Remote Frame is received, the CPU can be notified by the corresponding
RFPR set or IRR[2] (Remote Frame Request Interrupt), however, as RCAN-ET needs to transmit
the current message as a Data Frame, the RTR bit remains unchanged. In case of overrun
condition, the message received is discarded. Consequently, when a remote frame is causing
overrun (UMSR is set) into a Mailbox configured with ATX = 1/NMC = 0, the transmission of the
corresponding data frame is not carried out.
Important: In order to support automatic answer to remote frame when MBC = B'001 is used and
ATX = 1 the RTR flag must be programmed to zero to allow data frame to be transmitted.
Note: when a Mailbox is configured to send a remote frame request the DLC used for
transmission is the one stored into the Mailbox.
RTR
0
1
Description
Data frame
Remote frame
IDE (Identifier Extension bit): Used to distinguish between the standard format and extended
format of CAN data frames and remote frames.
IDE
Description
0
Standard format
1
Extended format
Rev. 2.00 Sep. 07, 2007 Page 817 of 1312
REJ09B0320-0200