Intel 8XC196NT Computer Hardware User Manual


 
87C196CB SUPPLEMENT
7-20
7.5 CONFIGURING MESSAGE OBJECTS
Each message object consists of a configuration register, a message identifier, control registers,
and data registers (from zero to eight bytes of data). This section explains how to configure mes-
sage objects and determine their status.
CAN_MSK15
(87C196CB)
Address:
Reset State:
1E0FH, 1E0EH,
1E0DH, 1E0CH
Unchanged
Program the CAN message 15 mask (CAN_MSK15) register to mask (“don’t care”) specific message
identifier bits for message 15 in addition to those bits masked by a global mask (CAN_EGMSK or
CAN_SGMSK).
31 24
87C196CB
MSK4 MSK3 MSK2 MSK1 MSK0
23 16
MSK12 MSK11 MSK10 MSK9 MSK8 MSK7 MSK6 MSK5
15 8
MSK20 MSK19 MSK18 MSK17 MSK16 MSK15 MSK14 MSK13
7 0
MSK28 MSK27 MSK26 MSK25 MSK24 MSK23 MSK22 MSK21
Bit
Number
Function
31:27 MSK4:0 ID Mask
These bits individually mask incoming message identifier (ID) bits.
0 = mask the ID bit (accept either “0” or “1”)
1 = accept only an exact match
26:24 Reserved. These bits are undefined; for compatibility with future devices,
do not modify these bits.
23:16
15:8
7:0
MSK12:5
MSK20:13
MSK28:21
ID Mask
These bits individually mask incoming message identifier (ID) bits.
0 = mask the ID bit (accept either “0” or “1”)
1 = accept only an exact match
Setting a CAN_MSK15 bit in any position that is cleared in the global mask register has no effect.
The message 15 mask is ANDed with the global mask, so any “don’t care” bits defined in a global
mask are also “don’t care” bits for message 15.
Figure 7-11. CAN Message 15 Mask (CAN_MSK15) Register