MC74AC259 Datasheet, PDF (2/9 Pages) ON Semiconductor – 8−Bit Addressable Latch

MC74AC259 MC74ACT259
MODE SELECT TABLE
E MR
Mode
L H Addressable Latch
H H Memory
L L Active HIGH 8-Channel Demultiplexer
H L Clear
H = HIGH Voltage Level
L = LOW Voltage Level
MODE SELECT-FUNCTION TABLE
Operating
Inputs
Outputs
Mode
MR E D A0 A1 A2 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
Master Reset L H X X X X L
L
L
L
L
L
L
L
L L d L L L Q=d L
L
L
L
L
L
L
L L d H L L L Q=d L
L
L
L
L
L
Demultiplex
(Active HIGH
Decoder when
L
•
L
•
d
•
LH
••
L
•
L
•
L Q=d L
•
•
•
L
•
L
•
L
•
L
•
D = H)
• •••••
•
•
•
•
•
•
•
•
• •••••
•
•
•
•
•
•
•
•
L L dHHH L
L
L
L
L
L
L Q=d
Store
(Do Nothing)
H H X X X X q0
q1
q2
q3
q4
q5
q6
q7
H L d L L L Q = d q1
q2
q3
q4
q5
q6
q7
H L d H L L q0 Q = d q2
q3
q4
q5
q6
q7
Addressable
Latch
H L d L H L q0
• •••••
•
q1 Q = d q3
•
•
•
q4
•
q5
•
q6
•
q7
•
• •••••
•
•
•
•
•
•
•
•
• •••••
•
•
•
•
•
•
•
•
H L d H H H q0
q1
q2
q3
q4
q5
q6 Q = d
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
d = HIGH or LOW Data one setup time prior to the LOW-to-HIGH Enable transition
q = Lower case letters indicate the state of the referenced output established during the last cycle in which it was addressed
or cleared.
FACT DATA
5-2