Diodes 74HCT594 - Manual (Page 3)

74HCT594
Document number: DS35491 Rev. 2 - 2
3 of 12
www.diodes.com
June 2013
© Diodes Incorporated
74HCT594
Functional Description and Timing Diagram
Control Input Output
Function
SHR STR SHCP STCP DS Q7S Qn
L X X X X L NC Clear Shift Register
X L X X X NC L Clear Storage Register
H X  L H or L Q6S NC Loads DS into shift register stage 0. All Q
S
shifted
H H X  X NC Qs Contents of shift register moved to starge register all Q
S
-> Q
N
H H   H or L Q6S QnS Shift Register one pulse count ahead of storage register.
H=HIGH voltage state
L=LOW voltage state
↑=LOW to HIGH transition
X= don’t care – high or low (not floating)
NC= No change
SHCP
DS
STCP
SHR
STR
Q0
Q1
Q6
Q7
Q7S