Chapter 14 Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12XDP512 Data Sheet, Rev. 2.11
Freescale Semiconductor 645
Read: For transmit buffers, anytime when TXEx flag is set (see Section 14.3.2.7, “MSCAN TransmitterFlag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (seeSection 14.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). For receive buffers,only when RXF flag is set (see Section 14.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”).
Register
Name Bit 7 654321Bit0
0x00X0
IDR0
RID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
W
0x00X1
IDR1
RID20 ID19 ID18 SRR (=1) IDE (=1) ID17 ID16 ID15
W
0x00X2
IDR2
RID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7
W
0x00X3
IDR3
RID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR
W
0x00X4
DSR0
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X5
DSR1
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X6
DSR2
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X7
DSR3
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X8
DSR4
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00X9
DSR5
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XA
DSR6
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XB
DSR7
RDB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W
0x00XC
DLR
RDLC3 DLC2 DLC1 DLC0
W
= Unused, always read ‘x’

Figure 14-23. Receive/Transmit Message Buffer — Extended Identifier Mapping