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XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
TwinCAN Module
User’s Manual
21-74
V2.2, 2004-01
TwinCAN_X1, V2.1
MSGFGCRHn (n = 31-0)
Message Object n FIFO/Gateway Control Register High
Reset Value: 0000
H
MSGFGCRLn (n = 31-0)
Message Object n FIFO/Gateway Control Register Low
Reset Value: 0000
H
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
MMC
0
CANPTR
r
rw
r
rwh
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
STT SDT
FD
0
DL
CC
IDC
SRR
EN
GD
FS
0
FSIZE
rw
rw
rw
r
rw
rw
rw
rw
r
rw
Field
Bits
Type
Description
FSIZE
[4:0]
Low
rw
FIFO Size Control
Bitfield FSIZE determines the number of message
objects combined to a FIFO buffer. Even numbered
message objects may provide FIFO base or slave
functionality, while odd numbered message objects are
restricted to slave functionality. In gateway mode, FSIZE
determines the length of the FIFO on the destination
side.
00000
B
message object n is part of a 1-stage FIFO
00001
B
message object n is part of a 2-stage FIFO
00011
B
message object n is part of a 4-stage FIFO
00111
B
message object n is part of a 8-stage FIFO
01111
B
message object n is part of a 16-stage FIFO
11111
B
message object n is part of a 32-stage FIFO
else
reserved
FSIZE = ‘00000’ leads to the behavior of a standard
message object (the pointer CANPTR used for this
action will not be changed). This value has to be written
if a gateway transfer to a single message object (no
FIFO) as destination is desired.
FSIZE is not evaluated for message objects configured
in standard mode, shared gateway mode or FIFO slave
functionality. In this case, FSIZE should be programmed
to ‘00000’.