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S912XEP100J5MAG Datasheet, PDF (628/1324 Pages) Freescale Semiconductor, Inc – Features of the MC9S12XE-Family are listed here. Please see Table D-2.for memory options and Table D-2. for the peripheral features that are available on the different family members. | |||
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Chapter 16 Freescaleâs Scalable Controller Area Network (S12MSCANV3)
16.3.2.17 MSCAN Identiï¬er Acceptance Registers (CANIDAR0-7)
On reception, each message is written into the background receive buffer. The CPU is only signalled to
read the message if it passes the criteria in the identiï¬er acceptance and identiï¬er mask registers
(accepted); otherwise, the message is overwritten by the next message (dropped).
The acceptance registers of the MSCAN are applied on the IDR0âIDR3 registers (see Section 16.3.3.1,
âIdentiï¬er Registers (IDR0âIDR3)â) of incoming messages in a bit by bit manner (see Section 16.4.3,
âIdentiï¬er Acceptance Filterâ).
For extended identiï¬ers, all four acceptance and mask registers are applied. For standard identiï¬ers, only
the ï¬rst two (CANIDAR0/1, CANIDMR0/1) are applied.
Module Base + 0x0010 to Module Base + 0x0013
7
R
AC7
W
6
AC6
5
AC5
Reset
0
0
0
4
AC4
0
3
AC3
0
Access: User read/write(1)
2
1
0
AC2
AC1
AC0
0
0
0
Figure 16-20. MSCAN Identiï¬er Acceptance Registers (First Bank) â CANIDAR0âCANIDAR3
1. Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
Table 16-22. CANIDAR0âCANIDAR3 Register Field Descriptions
Field
Description
7-0
AC[7:0]
Acceptance Code Bits â AC[7:0] comprise a user-deï¬ned sequence of bits with which the corresponding bits
of the related identiï¬er register (IDRn) of the receive message buffer are compared. The result of this comparison
is then masked with the corresponding identiï¬er mask register.
Module Base + 0x0018 to Module Base + 0x001B
7
R
AC7
W
6
AC6
5
AC5
Reset
0
0
0
4
AC4
0
3
AC3
0
2
AC2
0
Access: User read/write(1)
1
0
AC1
AC0
0
0
Figure 16-21. MSCAN Identiï¬er Acceptance Registers (Second Bank) â CANIDAR4âCANIDAR7
1. Read: Anytime
Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1)
MC9S12XE-Family Reference Manual Rev. 1.25
628
Freescale Semiconductor
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