September 1993 4
Philips Semiconductors Product specification
Octal bus transceiver/register; 3-state 74HC/HCT652
FUNCTION TABLE
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
↑ = LOW-to-HIGH transition
2. The data output functions may be enabled or disabled by various signals at OE
AB
and OE
BA
inputs. Data input
functions are always enabled, i.e., data at the bus inputs will be stored on every LOW-to-HIGH transition on the clock
inputs.
INPUTS
(1)
DATA I/O
(2)
OPERATION OR FUNCTION
OE
AB
OE
BA
CP
AB
CP
BA
S
AB
S
BA
A
1
THRU A
8
B
1
THRU B
8
HC/HCT652
L H H or L H or L X X
Input Input
Isolation
LH↑↑X X Store A and B data
XH↑H or L X X Input Not specified Store A, Hold B
HH↑↑L X Input Output Store A in both registers
L X H or L ↑ X X Not specified Input Hold A, Store B
LL↑↑X L Ouput Input Store B in both registers
LLXXXL
Ouput Input
Real Time B Data to A Bus
L L X H or L X H Stored B Data to A Bus
HHXXLX
Input Output
Real Time A Data to B Bus
H H H or L X H X Stored A Data to B Bus
H L H or L H or L H H Output Output
Stored A Data to B Bus and
Stored B Data to A Bus
Fig.4 Functional diagram.
