
CAN modules
UM0404
DocID13284 Rev 2
IFx command request registers
A message transfer is started as soon as the CPU has written the message number to the
Command Request Register. With this write operation the
Busy
bit is automatically set to
‘1’. After a wait time of 3 to 6 CAN clock
periods, the transfer between the Interface Register
and the Message RAM has completed and the
Busy
bit is set back to
zero
.
CAN1IF1CR (EF10h)
XBUS
Reset Value: 0001h
CAN2IF1CR (EE10h)
XBUS
Reset Value: 0001h
CAN1IF2CR (EF40h)
XBUS
Reset Value: 0001h
CAN2IF2CR (EE40h)
XBUS
Reset Value: 0001h
Note:
When a
Message Number
that is not valid is written into the Command Request Register,
the
Message Number
will be transformed into a valid value and that Message Object will be
transferred.
CAN Base + 0x22
IF1 Data B 1
CAN Base + 0x52
IF2 Data B 1
CAN Base + 0x24
IF1 Data B 2
CAN Base + 0x54
IF2 Data B 2
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Busy
-
-
-
-
-
-
-
-
-
Message Number
R
RW
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Busy
-
-
-
-
-
-
-
-
-
Message Number
R
RW
Bit
Function
Message
Number
Message Number
’00h’: Not a valid Message Number, interpreted as
20h
.
’01h’: Valid Message Number, the Message Object in the RAM is selected for data
transfer.
’02h’: Valid Message Number, the Message Object in the RAM is selected for data
transfer.
’20h’: Valid Message Number, the Message Object in the RAM is selected for data
transfer.
’21h’: Not a valid Message Number, interpreted as
01h
.
’22h’: Not a valid Message Number, interpreted as
02h
.
’3Fh’: Not a valid Message Number, interpreted as
1Fh.
Busy
Busy Flag
’0’: Reset to
zero
when read/write action has finished.
’1’: Set to
one
when writing to the IFx Command Request Register.
Table 61. IF1 and IF2 message interface register sets
Address
IF1 register set
Address
IF2 register set