MC68HC08AZ16 Datasheet, PDF (358/527 Pages) Motorola, Inc – HCMOS Microcontroller Unit

msCAN08 Controller (msCAN08)
Identifier acceptance filter
The Identifier Acceptance Registers (CIAR) defines the acceptable
pattern of the standard or extended identifier (ID10 - ID0 or ID28 - ID0).
Any of these bits can be marked ‘don’t care’ in the Identifier Mask
Register (CIMR).
ID28 IDR0 ID21 ID20 IDR1 ID15 ID14 IDR2 ID7 ID6 IDR3 RTR
ID10 IDR0 ID3 ID2 IDR1 IDE ID10 IDR2 ID3 ID10 IDR3 ID3
AM7 CIDMR0AM0 AM7 CIDMR1AM0 AM7 CIDMR2AM0 AM7 CIDMR3AM0
AC7 CIDAR0 AC0 AC7 CIDAR1 AC0 AC7 CIDAR2 AC0 AC7 CIDAR3 AC0
ID Accepted (Filter 0 Hit)
Figure 3. Single 32-bit maskable identifier acceptance filter
The background buffer RxBG will be copied into the foreground buffer
RxFG and the RxF flag will be set only in case of an accepted identifier
(an identifier acceptance filter hit). A hit will also cause a receiver
interrupt if enabled.
A filter hit is indicated to the application software by a set RXF (Receive
Buffer Full Flag, see msCAN08 receiver flag register (CRFLG) on page
382) and two bits in the Identifier Acceptance Control Register (see
msCAN08 Identifier Acceptance Control Register (CIDAC) on page
388). These Identifier Hit Flags (IDHIT1-0) clearly identify the filter
section that caused the acceptance. They simplify the application
software’s task to identify the cause of the receiver interrupt. In case that
more than one hit occurs (two or more filters match) the lower hit has
priority.
11-can
MOTOROLA
msCAN08 Controller (msCAN08)
MC68HC08AZ32
357