HCTS299MS

FN3069 Rev 1.00

Page 3 of 12

August 1995

TRUTH TABLE

Register Operating Modes

FUNCTION

INPUTS

REGISTER OUTPUTS

MR

CP

S0

S1

DS0

DS7

I/On

Q0

Q1

. . .

Q6

Q7

Reset (Clear)

L

X

XXXXX

L

L

. . .

L

L

Shift Right

H

h

l

l

X

X

L

q0

. . .

q5

q6

H

h

l

h

X

X

H

q0

. . .

q5

Q6

Shift Left

H

l

h

X

l

X

q1

q2

. . .

q7

L

H

l

h

X

h

X

q1

q2

. . .

q7

H

Hold (Do Nothing)

H

l

l

X

X

X

q0

q1

. . .

q6

q7

Parallel Load

H

h

h

X

X

l

L

L

. . .

L

L

H

h

h

X

X

h

H

H

. . .

H

H

TRUTH TABLE

Three-State I/O Port Operating Mode

FUNCTION

INPUTS

INPUTS/OUTPUTS

OE1

OE2

S0

S1

Qn (REGISTER)

I/O0 . . . I/O7

Read Register

L

L

L

X

L

L

LLL

X

H

H

LL

X

L

L

L

LL

X

L

H

H

Load Register

X

X

H

H

Qn = I/On

I/On = Inputs

Disable I/O

H

X

X

X

X

Z

XHX

X

X

Z

H = HighVoltage Level

L = Low Voltage Level

X = Immaterial

Z = Output in High Impedance State

h = Input Voltage High One Setup Time Prior Clock Transition

l = Input voltage Low One Setup Time Prior Clock Transition

= Low-to-High Clock Transition

qn = Lower Case Letter Indicates the State of the Referenced Output One Setup Time Prior Clock Transition