74F670 Datasheet, PDF (3/12 Pages) NXP Semiconductors – 4 x 4 register file 3-State

Philips Semiconductors
4 x 4 register file (3-State)
Product specification
74F670
LOGIC SYMBOL
14 13 5 4 15 1 2 3
WA WB RA RB D0 D1 D2 D3
12
WE
11
RE
Q0 Q1 Q2 Q3
V_CC=Pin 16
GND=Pin 8
10 9 7 6
SF01179
WORD SELECT FUNCTION TABLE
WRITE MODE
READ MODE
OPERATING MODE
WB
WA
RB
RA
Word Selected
L
L
L
L
Word 0
L
H
L
H Word 1
H
L
H
L
Word 2
H
H
H
H = High voltage level
L = Low voltage level
H Word 3
READ MODE FUNCTION TABLE
INPUT
RE
INTERNAL
LATCHES*
OUTPUT
Qn
OPERATING MODE
L
L
L
H
L
Read
H
H
X
Z
Disabled
H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance “off” state
* = The selection of “internal latches” by Read Address
(RA and RB) are not constrained by WE or RE operation.
LOGIC SYMBOL (IEEE/IEC)
RAM 4X4
14
13
0
1
1A
0
3
5
4
0
1
2A
0
3
12
C4 [WRITE]
11
EN [READ]
15
1A, 4D
1
2A
2
3
10
9
7
6
SF01180
WRITE MODE FUNCTION TABLE
INPUTS
WE
Dn
INTERNAL
LATCHES*
OPERATING MODE
L
L
L
H
L
Write data
H
H
X
NC
Data latched
H = High voltage level
L = Low voltage level
NC= No change
X = Don’t care
* = The write address (WA and WB) to the “internal latches”
must be stabled while WE is Low for conventional operation.
1990 Jul 12
3