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MC9S12KT256 Datasheet, PDF (296/594 Pages) Freescale Semiconductor, Inc – Microcontrollers | |||
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R
W
Reset:
7
ID20
6
ID19
5
ID18
4
SRR (=1)
3
IDE (=1)
2
ID17
1
ID16
x
x
x
x
x
x
x
Figure 9-24. Identiï¬er Register 1 (IDR1) â Extended Identiï¬er Mapping
0
ID15
x
Table 9-27. IDR1 Register Field Descriptions â Extended
Field
7:5
ID[20:18]
4
SRR
3
IDE
2:0
ID[17:15]
Description
Extended Format Identiï¬er â The identiï¬ers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signiï¬cant bit and is transmitted ï¬rst on the CAN bus during the arbitration procedure. The priority of an
identiï¬er is deï¬ned to be highest for the smallest binary number.
Substitute Remote Request â This ï¬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.
ID Extended â This ï¬ag indicates whether the extended or standard identiï¬er format is applied in this buffer. In
the case of a receive buffer, the ï¬ag is set as received and indicates to the CPU how to process the buffer
identiï¬er registers. In the case of a transmit buffer, the ï¬ag indicates to the MSCAN what type of identiï¬er to send.
0 Standard format (11 bit)
1 Extended format (29 bit)
Extended Format Identiï¬er â The identiï¬ers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signiï¬cant bit and is transmitted ï¬rst on the CAN bus during the arbitration procedure. The priority of an
identiï¬er is deï¬ned to be highest for the smallest binary number.
7
6
5
4
3
2
1
0
R
ID14
ID13
ID12
ID11
ID10
ID9
ID8
ID7
W
Reset:
x
x
x
x
x
x
x
x
Figure 9-25. Identiï¬er Register 2 (IDR2) â Extended Identiï¬er Mapping
Table 9-28. IDR2 Register Field Descriptions â Extended
Field
7:0
ID[14:7]
Description
Extended Format Identiï¬er â The identiï¬ers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the
most signiï¬cant bit and is transmitted ï¬rst on the CAN bus during the arbitration procedure. The priority of an
identiï¬er is deï¬ned to be highest for the smallest binary number.
MC9S12KT256 Data Sheet, Rev 1.15
296
Freescale Semiconductor
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