P8XC591 Datasheet, PDF (54/160 Pages) NXP Semiconductors – Single-chip 8-bit microcontroller with CAN controller

Philips Semiconductors
Single-chip 8-bit microcontroller with CAN controller
Preliminary Specification
P8xC591
For a successful reception of a message, all single bit
comparisons of at least one complete filter have to signal
acceptance. In case of a set RTR bit or a data length code
of “0” no data byte is existing. Nevertheless, a message
may pass Filter 1, if the first part up to the RTR bit signals
acceptance.
If no data byte filtering is required for Filter 1, the four least
significant bits of AMR1 and AMR3 have to be set “1”
(don‘t care). Then both filters are working identically using
the standard identifier range including the RTR bit.
Dual Filter Extended Frame:
If the Extended Frame Format is selected, the two defined
filters are looking identically. Both filters are comparing the
first two bytes of the Extended Identifier range only.
For a successful reception of a message, all single bit
comparisons of at least one complete filter have to signal
acceptance.
handbook, full pagewidth
Filter 1
MSB
LSB MSB
LSB
Addr.: 16
ACR0
Addr.: 17
ACR1
76543210 76543210
MSB
Addr.: 20
7654
LSB
AMR0
3210
MSB
Addr.: 21
7654
LSB
AMR1
3210
Message
Filter 2
Addr.: 22
7654
MSB
AMR2
3210
LSB
Addr.: 23
7654
MSB
AMR3
3210
LSB
Addr.: 18
7654
MSB
ACR2
3210
LSB
Addr.: 19
7654
MSB
ACR3
3210
LSB
Filter 1
...
Acceptance Mask Bit
Acceptance Code Bit
=
Message Bit
=
[7]
&
[6] _{... ... ...}
≥1
[0]
1 accepted
≥1 0 not accepted
Acceptance Code Bit
Acceptance Mask Bit
...
Filter 2
≥1 [0]
&
... ... ...
[6]
[7]
MHI018
Fig.18 Dual Filter Configuration, receiving Extended Frame Messages.
2000 Jul 26
54