CHAPTER 19 FCAN CONTROLLER (V850/SC3)
User’s Manual U15109EJ3V0UD
597
19.5.13 CAN global status register (CGST)
The CGST register indicates global status information.
This register can be read/written in 16-bit units.
Cautions 1. Both bitwise writing and direct writing to the CGST register are prohibited. Attempts to write
directly to this register may result in operation faults, so be sure to follow the sequence
described in 19.6 Cautions Regarding Bit Set/Clear Function.
2. When writing to the CGST register, set or clear bits according to the register configuration
shown in part (b) Write of the following figure.
(1/2)
After reset: 0000H
R/W
Address: xx3FFC10H
(a) Read
15
14
13
12
11
10
9
8
CGST
0
0
0
0
0
0
0
0
7
6
5
4
3
2
1
0
MERR
0
0
0
EFSD
TSM
0
GOM
(b) Write
15
14
13
12
11
10
9
8
CGST
0
0
0
0
set EFSD
set TSM
0
set GOM
7
6
5
4
3
2
1
0
clear MERR
0
0
0
clear EFSD clear TSM
0
clear GOM
(a) Read
MERR
MAC error status flag
0
Error does not occur after the MERR bit has been cleared
1
Error occurs at least once after MERR bit has been cleared
•
MAC errors occur under the following conditions.
•
When invalid address is accessed
•
When access prohibited by MAC is performed
•
When the GOM bit is cleared (0) before the INIT bit of the CnCTRL register is set (1)
EFSD
Shutdown request
0
Shutdown prohibited
1
Shutdown enabled
•
Be sure to set the EFSD bit (1) before clearing the GOM bit (0) (must be accessed twice).
The EFSD bit will be cleared (0) automatically when the CGST register is accessed again.
TSM
Operation status of time stamp counter
Note
0
Time stamp counter is stopped
1
Time stamp counter is operating
Note
Refer to
19.5.16 CAN time stamp count register (CGTSC)
.