Philips Semiconductors
Product specification
8-bit bidirectional binary counter (3-State)
74F1779
FEATURES
•
Multiplexed 3-State I/O ports for bus oriented applications
•
Built-in look-ahead carry capability
•
Center power pins to reduce effects of package inductance
•
Count frequency 145MHz typical
•
Supply current 90mA typical
•
See 74F269 for 24-pin separate I/O port version
•
See 74F579 for 20-pin version
•
See 74F779 for 16-pin version with abbreviated function table
DESCRIPTION
The 74F1779 is a fully synchronous 8-stage up/down counter with
multiplexed 3-State I/O ports for bus-oriented applications. All
control functions (hold, count up, count down, synchronous load) are
controlled by two mode pins (S0, S1). The device also features carry
look-ahead for easy cascading. All state changes are initiated by the
rising edge of the clock. When CET is High, the data outputs are
held in their current state and TC is held High. the TC output is not
recommended for use as a clock or asynchronous reset due to the
possibility of decoding spikes.
The 74F1779 differs from 74F779 in that it has an additional hold
mode as described in the Function Table.
PIN CONFIGURATION
I/O1 1
I/O2
I/O3
GND
I/O4
I/O5
2
3
4
5
6
16 I/O0
15 CP
14 CET
13 V
CC
12 TC
11 S0
10 S1
9
OE
I/O6 7
I/O7
8
SF01259
TYPE
74F1779
TYPICAL f
MAX
130MHz
TYPICAL
SUPPLY CURRENT
(TOTAL)
100mA
ORDERING INFORMATION
DESCRIPTION
16-pin Plastic DIP
16-pin Plastic SOL
COMMERCIAL RANGE
V
CC
= 5V
±10%,
T
amb
= 0°C to +70°C
N74F1779N
N74F1779D
PACKAGE
DRAWING
NUMBER
SOT38-4
SOT162-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
I/On
S0, S1
OE
CET
CP
TC
Data inputs
Data outputs
Select inputs
Output Enable input (active Low)
Count Enable Trickle input (active Low)
Clock input (active rising edge)
Terminal Count output (active Low)
DESCRIPTION
74F(U.L.)
HIGH/LOW
3.5/1.0
150/40
1.0/1.0
1.0/1.0
1.0/1.0
1.0/1.0
50/33
LOAD VALUE
HIGH/LOW
70µA/0.6mA
3.0mA/24mA
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
1.0mA/20mA
NOTE:
One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state.
1989 Apr 06
2
853–1367 96245
Philips Semiconductors
Product specification
8-bit bidirectional binary counter (3-State)
74F1779
LOGIC SYMBOL
11
10
FUNCTION TABLE
INPUTS
OPERATING MODE
S1
S0
S1
TC
12
S0
X
X
L
CET
X
X
X
H
X
L
L
OE
H
L
H
X
X
X
X
CP
X
X
↑
↑
↑
↑
↑
I/O0 to I/O7 in High impedance
Flip-flop outputs appear on I/O lines
Parallel load all flip-flops
Hold (TC held High)
Hold
Count up
Count down
X
X
L
14
15
9
CET
CP
OE
I/O0 I/O1 I/O2 I/O3 I/O4 I/O5 I/O6 I/O7
(not LL)
H
H
L
H
V
CC
=Pin 13
GND=Pin 4
16
1
2
3
5
6
7
8
H
SF01260
L
IEC/IEEE SYMBOL
CTR DIV 256
11
10
14
15
9
LOAD
0
M — DOWN
3 UP
HOLD
0
1
EN4
H = High voltage level
L = Low voltage level
X = Don’t care
↑
= Low-to-High clock transition
(not LL) = S0 and S1 should never be Low voltage level at the
same time in the hold mode only.
2 +/C5
1–
EN6
[1]
[2]
[4]
[8]
[16]
[32]
[64]
[128]
4, 5, 8 CT=256
4, 5, 8 CT=0
7
8
12
6
16
1
2
3
5
6
SF01261
1989 Apr 06
3
Philips Semiconductors
Product specification
8-bit bidirectional binary counter (3-State)
74F1779
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limits set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free-air temperature range.)
SYMBOL
V
CC
V
IN
I
IN
V
OUT
I
O
OUT
T
amb
T
stg
Supply voltage
Input voltage
Input current
Voltage applied to output in High output state
TC
Current applied to output in Low output state
Operating free-air temperature range
Storage temperature
I/On
PARAMETER
RATING
–0.5 to +7.0
–0.5 to +7.0
–30 to +5
–0.5 to V
CC
40
48
0 to +70
–65 to +150
UNIT
V
V
mA
V
mA
mA
°C
°C
RECOMMENDED OPERATING CONDITIONS
LIMITS
SYMBOL
V
CC
V
IH
V
IL
I
IK
I
O
OH
Supply voltage
High-level input voltage
Low-level input voltage
Input clamp current
TC
High-level
High level output current
I/On
TC
I
O
OL
T
amb
Low level output current
Low-level
Operating free-air temperature range
I/On
0
PARAMETER
MIN
4.5
2.0
0.8
–18
–1
–3
20
24
70
NOM
5.0
MAX
5.5
UNIT
V
V
V
mA
mA
mA
mA
mA
°C
1989 Apr 06
5
Embedded System
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