Freescale’s Scalable Controller Area Network (S12MSCANV3)
Table 8-18. CANIDAC Register Field Descriptions
Field
Description
5-4
Identifier Acceptance Mode — The CPU sets these flags to define the identifier acceptance filter organization
IDAM[1:0] (see Section 8.4.3, “Identifier Acceptance Filter”). Table 8-19 summarizes the different settings. In filter closed
mode, no message is accepted such that the foreground buffer is never reloaded.
2-0
Identifier Acceptance Hit Indicator — The MSCAN sets these flags to indicate an identifier acceptance hit (see
IDHIT[2:0] Section 8.4.3, “Identifier Acceptance Filter”). Table 8-20 summarizes the different settings.
Table 8-19. Identifier Acceptance Mode Settings
IDAM1
IDAM0
Identifier Acceptance Mode
0
0
1
1
0
1
0
1
Two 32-bit acceptance filters
Four 16-bit acceptance filters
Eight 8-bit acceptance filters
Filter closed
Table 8-20. Identifier Acceptance Hit Indication
IDHIT2
IDHIT1
IDHIT0
Identifier Acceptance Hit
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Filter 0 hit
Filter 1 hit
Filter 2 hit
Filter 3 hit
Filter 4 hit
Filter 5 hit
Filter 6 hit
Filter 7 hit
The IDHITx indicators are always related to the message in the foreground buffer (RxFG). When a
message gets shifted into the foreground buffer of the receiver FIFO the indicators are updated as well.
8.3.2.13 MSCAN Reserved Register
This register is reserved for factory testing of the MSCAN module and is not available in normal system
operating modes.
S12P-Family Reference Manual, Rev. 1.13
270
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