Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV2)
328
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
— a) the 14 most significant bits of the extended identifier plus the SRR and IDE bits of CAN 2.0B
messages or
— b) the 11 bits of the standard identifier, the RTR and IDE bits of CAN 2.0A/B messages.
shows how the first 32-bit filter bank (CANIDAR0–CANIDA3,
CANIDMR0–3CANIDMR) produces filter 0 and 1 hits. Similarly, the second filter bank
(CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces filter 2 and 3 hits.
•
Eight identifier acceptance filters, each to be applied to the first 8 bits of the identifier. This mode
implements eight independent filters for the first 8 bits of a CAN 2.0A/B compliant standard
identifier or a CAN 2.0B compliant extended identifier.
shows how the first 32-bit
filter bank (CANIDAR0–CANIDAR3, CANIDMR0–CANIDMR3) produces filter 0 to 3 hits.
Similarly, the second filter bank (CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7)
produces filter 4 to 7 hits.
•
Closed filter. No CAN message is copied into the foreground buffer RxFG, and the RXF flag is
never set.
Figure 10-39. 32-bit Maskable Identifier Acceptance Filter
ID28
ID21
IDR0
ID10
ID3
IDR0
ID20
ID15
IDR1
ID2
IDE
IDR1
ID14
ID7
IDR2
ID10
ID3
IDR2
ID6
RTR
IDR3
ID10
ID3
IDR3
AC7
AC0
CANIDAR0
AM7
AM0
CANIDMR0
AC7
AC0
CANIDAR1
AM7
AM0
CANIDMR1
AC7
AC0
CANIDAR2
AM7
AM0
CANIDMR2
AC7
AC0
CANIDAR3
AM7
AM0
CANIDMR3
ID Accepted (Filter 0 Hit)
CAN 2.0B
Extended Identifier
CAN 2.0A/B
Standard Identifier
Summary of Contents for MC9S12C Family
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