Chapter 16 Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12XE-Family Reference Manual , Rev. 1.21
632
Freescale Semiconductor
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16.3.3.1.1
IDR0–IDR3 for Extended Identier Mapping
Module Base + 0x00X0
76543210
R
ID28
ID27
ID26
ID25
ID24
ID23
ID22
ID21
W
Reset:
xxxxxxxx
Figure 16-26. Identier Register 0 (IDR0) — Extended Identier Mapping
Table 16-27. IDR0 Register Field Descriptions — Extended
Field
Description
7-0
ID[28:21]
Extended Format Identier — The identiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signicant bit and is transmitted rst on the CAN bus during the arbitration procedure. The priority of an
identier is dened to be highest for the smallest binary number.
Module Base + 0x00X1
76543210
R
ID20
ID19
ID18
SRR (=1)
IDE (=1)
ID17
ID16
ID15
W
Reset:
xxxxxxxx
Figure 16-27. Identier Register 1 (IDR1) — Extended Identier Mapping
Table 16-28. IDR1 Register Field Descriptions — Extended
Field
Description
7-5
ID[20:18]
Extended Format Identier — The identiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signicant bit and is transmitted rst on the CAN bus during the arbitration procedure. The priority of an
identier is dened to be highest for the smallest binary number.
4
SRR
Substitute Remote Request — This xed recessive bit is used only in extended format. It must be set to 1 by
the user for transmission buffers and is stored as received on the CAN bus for receive buffers.
3
IDE
ID Extended — This ag indicates whether the extended or standard identier format is applied in this buffer. In
the case of a receive buffer, the ag is set as received and indicates to the CPU how to process the buffer
identier registers. In the case of a transmit buffer, the ag indicates to the MSCAN what type of identier to send.
0 Standard format (11 bit)
1 Extended format (29 bit)
2-0
ID[17:15]
Extended Format Identier — The identiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signicant bit and is transmitted rst on the CAN bus during the arbitration procedure. The priority of an
identier is dened to be highest for the smallest binary number.