beautypg.com

B&B Electronics PCI-1711 - Manual User Manual

Page 103

background image

Appendix D

– 95 –

PCI-1710 series User’s Manual

Advantech Co., Ltd.
www.advantech.com

M2, M1 & M0 Select operating mode

M2

M1

M0

Mode

Description

0

0

0

0

Stop on terminal count

0

0

1

1

Programmable one shot

X

1

0

2

Rate generator

X

1

1

3

Square wave rate generator

1

0

0

4

Software triggered strobe

1

0

1

5

Hardware triggered strobe

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

D4

D3

D2

D1

D0

Value

1

1

CNT

STA

C2

C1

C0

X

CNT = 0

Latch count of selected counter(s)

STA = 0

Latch status of selected counter(s)

C2, C1 & C0

Select counter for a read-back operation
C2 = 1 select Counter 2
C1 = 1 select Counter 1
C0 = 1 select Counter 0

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. The
data format of the counter read/write register then becomes: