74F552 Datasheet, PDF (4/14 Pages) NXP Semiconductors – Octal registered transceiver with parity and flags 3-State

Philips Semiconductors
Octal registered transceiver with parity and flags (3-State)
Product specification
74F552
R or S FLAG FUNCTION TABLE
CEX
INPUTS
CPX
OEXX
OUTPUTS
FR or FS
H
X
↑
NC
L
↑
↑
H
X
X
↑
L
H = High voltage level
L = Low voltage level
NC= No change
X = Don’t care
X = R or S for CPX and CEX
XX= AS or BR
↑ = Low-to-High transition
↑ _{= Not Low-to-High transition}
PARITY CHECK FUNCTION TABLE
INPUTS
OEAS
CPS
PARITY
H
X
X
L
↑
L
L
↑
L
L
↑
H
L
↑
H
H = High voltage level
L = Low voltage level
X = Don’t care
↑ = Low-to-High transition
OPERATING
MODE
Hold flag
Set flag
Clear flag
PARITY GENERATION FUNCTION TABLE
INPUTS
OEBR CPR
OUTPUTS
Number of Highs
in the Q outputs PARITY
of the R register
OPERATING
MODE
H
X
X
Z
Hold flag
L
↑
L
↑
0,2,4,6,8
1,3,5,7
H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance “off” state
↑ = Low-to-High transition
H
L
Load data
OUTPUTS
Number of Highs in the Q outputs
of the R register
X
0,2,4,6,8
1,3,5,7
0,2,4,6,8
1,3,5,7
ERROR
H
L
H
H
L
OPERATING MODE
Parity check
1991 Jan 02
4