COBHAM GR712RC - Page 150

GR712RC-UM, Jun 2017, Version 2.9 150 www.cobham.com/gaisler
GR712RC
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Single filter mode, standard frame
When receiving a standard frame in single filter mode the registers ACR0-3 are compared against the
incoming message in the following way:
ACR0.7-0 & ACR1.7-5 are compared to ID.28-18
ACR1.4 is compared to the RTR bit.
ACR1.3-0 are unused.
ACR2 & ACR3 are compared to data byte 1 & 2.
The corresponding bits in the AMR registers selects if the results of the comparison doesn’t matter. A
set bit in the mask register means don’t care.
Single filter mode, extended frame
When receiving an extended frame in single filter mode the registers ACR0-3 are compared against
the incoming message in the following way:
ACR0.7-0 & ACR1.7-0 are compared to ID.28-13
ACR2.7-0 & ACR3.7-3 are compared to ID.12-0
ACR3.2 are compared to the RTR bit
ACR3.1-0 are unused.
The corresponding bits in the AMR registers selects if the results of the comparison doesn’t matter. A
set bit in the mask register means don’t care.
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Dual filter mode, standard frame
When receiving a standard frame in dual filter mode the registers ACR0-3 are compared against the
incoming message in the following way:
Filter 1
ACR0.7-0 & ACR1.7-5 are compared to ID.28-18
ACR1.4 is compared to the RTR bit.
ACR1.3-0 are compared against upper nibble of data byte 1
ACR3.3-0 are compared against lower nibble of data byte 1
Filter 2
ACR2.7-0 & ACR3.7-5 are compared to ID.28-18
ACR3.4 is compared to the RTR bit.
The corresponding bits in the AMR registers selects if the results of the comparison doesn’t matter. A
set bit in the mask register means don’t care.
Dual filter mode, extended frame
When receiving a standard frame in dual filter mode the registers ACR0-3 are compared against the
incoming message in the following way:
Table 151.Acceptance filter registers
Address Description
16 Acceptance code 0 (ACR0)
17 Acceptance code 1 (ACR1)
18 Acceptance code 2 (ACR2)
19 Acceptance code 3 (ACR3)
20 Acceptance mask 0 (AMR0)
21 Acceptance mask 1 (AMR1)
22 Acceptance mask 2 (AMR2)
23 Acceptance mask 3 (AMR3)