74174

Hex D flip-flop.

It used as bank register in ZX Spectrum 128K for memory paging.

Pinout

CLEAR [ 1Q [ 1D [ 2D [ 2Q [ 3D [ 3Q [ GND [

1 °       16 2         15 3         14 4         13 5         12 6         11 7         10 8         9

] VCC ] 6Q ] 6D ] 5D ] 5Q ] 4D ] 4Q ] CLK

Function table
(each flip-flop)

Inputs			Output
CLEAR	Clock	xD	xQ
L	X	X	L
H	↑	L	L
H	↑	H	H
H	X (not ↑)	X	xQO

H = high level (steady state)
L = low level (steady state)
X = irrelevant
↑ = transition from low to high level
xQ_O = the level of xQ before the indicated steady-state input conditions were established