Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
316
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
Write: For transmit buffers, anytime when TXEx flag is set (see
Section 10.3.2.7, “MSCAN Transmitter
”) and the corresponding transmit buffer is selected in CANTBSEL (see
Section 10.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)
”). Unimplemented for
receive buffers.
Reset: Undefined (0x00XX) because of RAM-based implementation
10.3.3.1
Identifier Registers (IDR0–IDR3)
The identifier registers for an extended format identifier consist of a total of 32 bits; ID[28:0], SRR, IDE,
and RTR bits. The identifier registers for a standard format identifier consist of a total of 13 bits; ID[10:0],
RTR, and IDE bits.
10.3.3.1.1
IDR0–IDR3 for Extended Identifier Mapping
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
IDR0
0x00X0
R
ID10
ID9
ID8
ID7
ID6
ID5
ID4
ID3
W
IDR1
0x00X1
R
ID2
ID1
ID0
RTR
IDE (=0)
W
IDR2
0x00X2
R
W
IDR3
0x00X3
R
W
= Unused, always read ‘x’
Figure 10-24. Receive/Transmit Message Buffer — Standard Identifier Mapping
Module Base + 0x00X1
7
6
5
4
3
2
1
0
R
ID28
ID27
ID26
ID25
ID24
ID23
ID22
ID21
W
Reset:
x
x
x
x
x
x
x
x
Figure 10-25. Identifier Register 0 (IDR0) — Extended Identifier Mapping
Table 10-24. IDR0 Register Field Descriptions — Extended
Field
Description
7:0
ID[28:21]
Extended Format Identifier —
The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an
identifier is defined to be highest for the smallest binary number.
Summary of Contents for MC9S12C Family
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