Advantech MIC-3716 Manual page 113

BCD Select binary or BCD counting
BCD Type
0 Binary counting 16-bits
1 Binary coded decimal (BCD) counting
If you set the module for binary counting, the count can be any
number from 0 up to 65535. If you set it for BCD (Binary Coded
Decimal) counting, the count can be any number from 0 to 9999.
If you set both SC1 and SC0 bits to 1, the counter control register is in
read-back command mode. The control register data format then
becomes:
BASE + 30(Dec) 82C54 control, read-back mode
Bit D7 D6 D5
Value 1 1
CNT = 0
STA = 0
C2, C1 & C0
If you set both SC1 and SC0 to 1 and STA to 0, the register selected
by C2 to C0 contains a byte which shows the status of the counter.
D4
CNT STA
Latch count of selected counter(s)
Latch status of selected counter(s)
Select counter for a read-back operation
C2 = 1 select Counter 2
C1 = 1 select Counter 1
C0 = 1 select Counter 0
D3 D2 D1 D0
C2 C1 C0 X
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