mc68hc08qa24 Freescale Semiconductor, Inc, mc68hc08qa24 Datasheet - Page 348

• Manufacturer Part Number: mc68hc08qa24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

CAN Controller
22.6 Identifier Acceptance Filter
Technical Data
346
A flexible, programmable generic identifier acceptance filter has been
introduced to reduce the CPU interrupt loading. The filter is
programmable to operate in three different modes:
The identifier acceptance registers (CIAR) define 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).
Figure 22-3. Single 32-Bit Maskable Identifier Acceptance Filter
•
•
•
AC7
AC7
ID28
ID10
Single identifier acceptance filter to be applied to the full 29 bits of
the identifier and to these bits of the CAN frame: RTR, IDE, and
SRR. This mode implements a single filter for a full length CAN
2.0B compliant extended identifier.
Double identifier acceptance filter to be applied to:
– The 11 bits of the identifier and the RTR bit of CAN 2.0A
– The 14 most significant bits of the identifier of CAN 2.0B
Quadruple identifier acceptance filter to be applied to the first eight
bits of the identifier. This mode implements four independent
filters for the first eight bits of a CAN 2.0A compliant standard
identifier.
CIDMR0
CIDAR0
messages or
messages
IDR0
IDR0
ID21
AC0
AC0
ID3
CAN Controller
AC7
AC7
ID20
ID2
CIDMR1
CIDAR1
IDR1
IDR1
ID Accepted (Filter 0 Hit)
IDE
ID15
AC0
AC0
AC7
AC7
ID14
ID10
CIDMR2
CIDAR2
IDR2
IDR2
AC0
AC0
ID7
ID3
Freescale Semiconductor
AC7
AC7
ID6
ID10
MC68HC08QA24
CIDMR3
CIDAR3
IDR3
IDR3
RTR
AC0
AC0
ID3