Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256 Manuale Utente

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DEMO9S12XHY256
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Freescale’s Scalable Controller Area Network (S12MSCANV3)
MC9S12XHY-Family Reference Manual, Rev. 1.04
368
Freescale Semiconductor
11.3.3.1.1
IDR0–IDR3 for Extended Identifier Mapping
Module Base + 0x00X0
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 11-26. Identifier Register 0 (IDR0) — Extended Identifier Mapping
Table 11-27. 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.
Module Base + 0x00X1
7
6
5
4
3
2
1
0
R
ID20
ID19
ID18
SRR (=1)
IDE (=1)
ID17
ID16
ID15
W
Reset:
x
x
x
x
x
x
x
x
Figure 11-27. Identifier Register 1 (IDR1) — Extended Identifier Mapping
Table 11-28. IDR1 Register Field Descriptions — Extended
Field
Description
7-5
ID[20:18]
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.
4
SRR
Substitute Remote Request — This fixed 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 flag indicates whether the extended or standard identifier format is applied in this buffer. In
the case of a receive buffer, the flag is set as received and indicates to the CPU how to process the buffer
identifier registers. In the case of a transmit buffer, the flag indicates to the MSCAN what type of identifier to send.
0 Standard format (11 bit)
1 Extended format (29 bit)
2-0
ID[17:15]
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.