74abt16899 NXP Semiconductors, 74abt16899 Datasheet - Page 5

• Manufacturer Part Number: 74abt16899
• Description: 18-bit Latched Transceiver With 16-bit Parity Generator/checker 3-state
• Manufacturer: NXP Semiconductors

Philips Semiconductors
BLOCK DIAGRAM
FUNCTION TABLE
H = High voltage level
L = Low voltage level
X = Don’t care
1998 Feb 25
OEB
EVEN
APAR
ODD/
OEA
18-bit latched transceiver with 16-bit
parity generator/checker (3-State)
H
H
H
H
H
H
LEA
SEL
L
L
L
L
L
L
A0
A1
A2
A3
A4
A5
A6
A7
OEA
H
H
H
H
H
H
L
L
L
L
L
L
INPUTS
SEL
H
H
H
H
X
L
L
L
L
L
L
X
LEA
X
H
X
X
H
H
H
H
H
X
L
L
LEB
LE
H
H
H
H
H
H
X
L
X
X
L
X
Transparent
OE
Latch
Output
9–bit
Buffer
9–bit
3-State A bus and B bus (input A & B simultaneously)
B
B
B
B
B
A
A
A
A
A
Output to A bus and B bus (NOT ALLOWED)
A, transparent B latch, generate parity from B0 - B7, check B bus parity
A, transparent A & B latch, generate parity from B0 - B7, check A & B bus parity
A, B bus latched, generate parity from latched B0 - B7 data, check B bus parity
A, transparent B latch, parity feed-through, check B bus parity
A, transparent A & B latch, parity feed-through, check A & B bus parity
B, transparent A latch, generate parity from A0 - A7, check A bus parity
B, transparent A & B latch, generate parity from A0 - A7, check A & B bus parity
B, A bus latched, generate parity from latched A0 - A7 data, check A bus parity
B, transparent A latch, parity feed-through, check A bus parity
B, transparent A & B latch, parity feed-through, check A & B bus parity
Generator
Parity
mux
1
0
5
Generator
Parity
OPERATING MODE
1
0
mux
(1 of 2 parity blocks)
Transparent
Latch
9–bit
Output
Buffer
9–bit
OE
LE
74ABTH16899
74ABT16899
Product specification
SH00084
B0
B1
B2
B3
B4
B5
B6
B7
BPAR
ERRA
ERRB
OEB
LEB