B&B Electronics PCI-1711 - Manual - Manual (Page 107)

Appendix D
– 99 – PCI-1710 series User’s Manual Advantech Co., Ltd.
www.advantech.com
The 82C54 supports the counter latch operation in two ways. The first
way is to set bits RW1 and RW0 to 0. This latches the count of the
selected counter in a 16-bit hold register. The second way is to perform
a latch operation under the read-back command. Set bits SC1 and SC0
to 1 and CNT = 0. The second method has the advantage of operating
several counters at the same time. A subsequent read operation on the
selected counter will retrieve the latched value.