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2

Function Table

H

= HIGH Voltage Level

X

= Immaterial

L

= LOW Voltage Level

 = LOW-to-HIGH Transition.

Note 1: The data output functions may be enabled or disabled by various signals at the G and DIR inputs. Data input functions are always enabled; i.e., data

at the bus pins will be stored on every LOW-to-HIGH transition of the appropriate clock inputs. Also applies to data I/O (A and B: 8-15) and #2 control pins.

Real Time Transfer

A-Bus to B-Bus

Real Time Transfer

B-Bus to A-Bus

Storage from

Bus to Register

Transfer from

Register to Bus

Inputs

Data I/O (Note 1)

Output Operation Mode

H

X

H or L

H or L

X

X

Isolation

HX



X

X

X

Input

Input

Clock An Data into A Register

HX

X



X

X

Clock Bn Data Into B Register

LH

X

X

L

X

An to Bn—Real Time (Transparent Mode)

LH



X

L

X

Input

Output

Clock An Data to A Register

L

H

H or L

X

H

X

A Register to Bn (Stored Mode)

LH



X

H

X

Clock An Data into A Register and Output to Bn

L

L

X

X

X

L

Bn to An—Real Time (Transparent Mode)

LL

X



X

L

Output

Input

Clock Bn Data into B Register

L

L

X

H or L

X

H

B Register to An (Stored Mode)

LL

X



X

H

Clock Bn into B Register and Output to An