Can message center movx register descriptions – Maxim Integrated High-Speed Microcontroller Users Guide: DS80C390 Supplement User Manual
Page 130
High-Speed Microcontroller User’s Guide: DS80C390 Supplement
130 of 158
CAN MESSAGE CENTER MOVX REGISTER DESCRIPTIONS
CAN Message Center y Arbitration Register 0 (CnMyAR0)
MOVX
Address
1
7
6
5
4
3
2
1
0
xxxxy2h ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21
CAN Message Center y Arbitration Register 1 (CnMyAR1)
MOVX
Address
1
7
6
5
4
3
2
1
0
xxxxy3h ID20 ID19 ID18 ID17 ID16 ID15 ID14 ID13
CAN Message Center y Arbitration Register 2 (CnMyAR2)
MOVX
Address
1
7
6
5
4
3
2
1
0
xxxxy4h
ID12
ID11 ID10 ID9 ID8 ID7 ID6 ID5
CAN Message Center y Arbitration Register 3 (CnMyAR3)
MOVX
Address
1
7
6
5
4
3
2
1
0
xxxxy5h
ID4 ID3 ID2 ID1 ID0 0 0 WTOE
ID28-ID0
CAN Message Center y Arbitration Registers 0–3. These bits form the
arbitration value/identification number for the message center y. When the
message center is configured in a transmit mode, these registers will be the source
of the 29-bit ID message field (when EX/ST =1) or the 11-bit ID message field
(when EX/ST =0). When EX/ST =1, the 29 message ID bits will correspond to
ID28-ID0 as shown above. When EX/ST =0, the message ID bits 10-0 correspond
to ID28-18 in CnMyAR0 and CnMyAR1.
When configured in a receive mode, these registers serve as the arbitration value
for message center y, against which incoming messages are compared to ascertain
if they are valid for that message center. When EX/ST =1, all 29 bits of the
arbitration are used, but when EX/ST =0, only the most significant 11 bits are
used.
Bits 2-1
(CnMyAR3 only)
Reserved
. Bits 2 and 1 of the CnMyAR3 register are not used in arbitration. These
bits can be modified in the application software.
WTOE
Bit 0
(CnMxAR3 only)
Writeover Enable. This bit controls the ability of a new message to overwrite an
existing message in the corresponding message center in receive mode. The
DTUP and EXTRQ bits for the message center in question must also be
considered to determine the effect of this bit as shown below. The WTOE bit
should only be programmed when the SWINT bit is set.