DATA SH EET
Product specification
File under Integrated Circuits, IC06 December 1990
INTEGRATED CIRCUITS
74HC/HCT670
4 x 4 register file; 3-state
For a complete data sheet, please also download:
•The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
December 1990 2
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
FEATURES
•Simultaneous and independent read and write
operations
•Expandable to almost any word size and bit length
•Output capability: bus driver
•ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT670 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT670 are 16-bit 3-state register files
organized as 4 words of 4 bits each. Separated read and
write address inputs (RA, RBand WA,W
B
) and enable
inputs (RE andWE) are available, permitting simultaneous
writing into one word location and reading from another
location. The 4-bit word to be stored is presented to four
data inputs (D0 to D3). The WA and WB inputs determine
the location of the stored word. When the WE input is
LOW, the data is entered into the addressed location. The
addressed location remains transparent to the data while
the WE input is LOW. Data supplied at the inputs will be
read out in true (non-inverting) form from the 3-state
outputs (Q0 to Q3). Dnand Wninputs are inhibited when
WE is HIGH.
Direct acquisition of data stored in any of the four registers
is made possible by individual read address inputs
(RAand RB). The addressed word appears at the four
outputs when the RE is LOW. Data outputs are in the high
impedance OFF-state when RE is HIGH. This permits
outputs to be tied together to increase the word capacity to
very large numbers.
Design of the read enable signals for the stacked devices
must ensure that there is no overlap in the LOW levels
which would cause more than one output to be active at
the same time. Parallel expansion to generate n-bit words
is accomplished by driving the enable and address inputs
of each device in parallel.
QUICK REFERENCE DATA
GND = 0 V; Tamb =25°C; tr=t
f= 6 ns
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW):
PD=C
PD ×VCC2×fi+∑ (CL×VCC2×fo) where:
fi= input frequency in MHz
fo= output frequency in MHz
∑(CL×VCC2×fo) = sum of outputs
CL= output load capacitance in pF
VCC = supply voltage in V
2. For HC the condition is VI= GND to VCC;
for HCT the condition is VI= GND to VCC −1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
SYMBOL PARAMETER CONDITIONS TYPICAL UNIT
HC HCT
tPHL/ tPLH propagation delay Dn to QnCL= 15 pF; VCC = 5 V 23 23 ns
CIinput capacitance 3.5 3.5 pF
CPD power dissipation capacitance per package notes 1 and 2 122 124 pF
December 1990 3
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
5, 4 RA, RBread address inputs
8 GND ground (0 V)
10, 9, 7, 6 Q0 to Q3data outputs
11 RE 3-state output read enable input (active LOW)
12 WE write enable input (active LOW)
14, 13 WA, WBwrite address inputs
15, 1, 2, 3 D0 to D3data inputs
16 VCC positive supply voltage
Fig.1 Pin configuration.
Fig.2 Logic symbol. Fig.3 IEC logic symbol. Fig.4 Functional diagram.
WRITE MODE SELECT TABLE
Note
1. The write address (WA and WB) to the
“internal latches” must be stable while WE is
LOW for conventional operation.
OPERATING
MODE INPUTS INTERNAL
LATCHES(1)
WE Dn
write data L
LL
HL
H
data latched H X no change
READ MODE SELECT TABLE
Notes
1. The selection of the “internal latches” by read address
(RA and RB) are not constrained by WE or RE operation.
H = HIGH voltage level
L = LOW voltage level
X = don’t care
Z = high impedance OFF-state
OPERATING
MODE INPUTS OUTPUT
RE INTERNAL LATCHES(1) Qn
read L
LL
HL
H
disabled H X Z
December 1990 4
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
Fig.5 Logic diagram.
December 1990 5
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: bus driver
ICC category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; tr=t
f= 6 ns; CL=50pF
SYMBOL PARAMETER
Tamb (°C)
UNIT
TEST CONDITIONS
74HC VCC
(V) WAVEFORMS+25 −40 to +85 −40 to+125
min. typ. max. min. max. min. max.
tPHL/ tPLH propagation delay
RA, RB to Qn
58
21
17
195
39
33
245
49
42
295
59
50
ns 2.0
4.5
6.0
Fig.6
tPHL/ tPLH propagation delay
WE to Qn
77
28
22
250
50
43
315
63
54
375
75
64
ns 2.0
4.5
6.0
Fig.7
tPHL/ tPLH propagation delay
Dn to Qn
74
27
22
250
50
43
315
63
54
375
75
64
ns 2.0
4.5
6.0
Fig.7
tPZH/ tPZL 3-state output enable time
RE to Qn
39
14
11
150
30
26
190
38
33
225
45
38
ns 2.0
4.5
6.0
Fig.9
tPHZ/ tPLZ 3-state output disable time
RE to Qn
47
17
14
150
30
26
190
38
33
225
45
38
ns 2.0
4.5
6.0
Fig.9
tTHL/ tTLH output transition time 14
5
4
60
12
10
75
15
13
90
18
15
ns 2.0
4.5
6.0
Fig.6
tWwrite enable pulse width
LOW 80
16
14
14
5
4
100
20
17
120
24
20
ns 2.0
4.5
6.0
Fig.8
tsu set-up time
Dn to WE 60
12
10
3
1
1
75
15
13
90
18
15
ns 2.0
4.5
6.0
Fig.8
tsu set-up time
WA, WB to WE 60
12
10
6
2
2
75
15
13
90
18
15
ns 2.0
4.5
6.0
Fig.8
thhold time
Dn to WE 5
5
5
0
0
0
5
5
5
5
5
5
ns 2.0
4.5
6.0
Fig.8
thhold time
WA, WB to WE 5
5
5
0
0
0
5
5
5
5
5
5
ns 2.0
4.5
6.0
Fig.8
tlatch latch time
WE to RA, RB
100
20
17
28
10
8
125
25
21
150
30
26
ns 2.0
4.5
6.0
Fig.8
December 1990 6
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: bus driver
ICC category: MSI
Note to HCT types
The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications.
To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below.
INPUT UNIT LOAD COEFFICIENT
Dn
WE, WA
WB
0.25
0.40
0.60
RA
RB
RE
0.70
1.10
1.35
December 1990 7
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; tr=t
f= 6 ns; CL=50pF
SYMBOL PARAMETER
Tamb (°C)
UNIT
TEST CONDITIONS
74HCT VCC
(V) WAVEFORMS+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
tPHL/ tPLH propagation delay
RA, RB to Qn
21 40 50 60 ns 4.5 Fig.6
tPHL/ tPLH propagation delay
WE to Qn
28 50 63 75 ns 4.5 Fig.7
tPHL/ tPLH propagation delay
Dn to Qn
27 50 63 75 ns 4.5 Fig.7
tPZH/ tPZL 3-state output enable time
RE to Qn
18 35 44 53 ns 4.5 Fig.9
tPHZ/ tPLZ 3-state output disable time
RE to Qn
19 35 44 53 ns 4.5 Fig.9
tTHL/ tTLH output transition time 5 12 15 18 ns 4.5 Fig.6
tWwrite enable pulse width
LOW 18 9 23 27 ns 4.5 Fig.8
tsu set-up time
Dn to WE 12 4 15 18 ns 4.5 Fig.8
tsu set-up time
WA, WB to WE 12 −2 15 18 ns 4.5 Fig.8
thhold time
Dn to WE 5−1 5 5 ns 4.5 Fig.8
thhold time
WA, WB to WE 5 0 5 5 ns 4.5 Fig.8
tlatch latch time
WE to RA, RB
25 11 31 38 ns 4.5 Fig.8
December 1990 8
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
AC WAVEFORMS
Fig.6 Waveforms showing the read address input
(RA, RB) to output (Qn) propagation delays
and output transition times.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
Fig.7 Waveforms showing the write enable input
(WE) and data input (Dn) to output (Qn)
propagation delays, and the write enable
pulse width.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
Fig.8 Waveforms showing the write address input (WA, WB) and data input (Dn) to write enable (WE) set-up,
hold and latch times.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
The shaded areas indicate when the input is permitted
to change for predictable output performance.
The time allowed for the internal output of the latch to
assume the state of the new data (tlatch) is important
only when attempting to read from a location
immediately after that location has received new data.
This parameter is measured from the falling edge of
WE to the rising edge of RA or RB, RE must be LOW.
December 1990 9
Philips Semiconductors Product specification
4 x 4 register file; 3-state 74HC/HCT670
PACKAGE OUTLINES
See
“74HC/HCT/HCU/HCMOS Logic Package Outlines”
.
Fig.9 Waveforms showing the read enable (RE) to output (Qn) enable and disable times, and the read enable
pulse width.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
