MC14557B Datasheet, PDF (1/6 Pages) Motorola, Inc – 1-TO-64 BIT VARIABLE LENGTH SHIFT REGISTER

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
1-to-64 Bit Variable Length
Shift Register
The MC14557B is a static clocked serial shift register whose length may
be programmed to be any number of bits between 1 and 64. The number of
bits selected is equal to the sum of the subscripts of the enabled Length
Control inputs (L1, L2, L4, L8, L16, and L32) plus one. Serial data may be
selected from the A or B data inputs with the A/B select input. This feature is
useful for recirculation purposes. A Clock Enable (CE) input is provided to
allow gating of the clock or negative edge clocking capability.
The device can be effectively used for variable digital delay lines or simply
to implement odd length shift registers.
• 1–64 Bit Programmable Length
• Q and Q Serial Buffered Outputs
• Asynchronous Master Reset
• All Inputs Buffered
• No Limit On Clock Rise and Fall Times
• Supply Voltage Range = 3.0 Vdc to 18 Vdc
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ • Capable of Driving Two Low–power TTL Loads or one Low–power
Schottky TTL Load Over the Rated Temperature Range
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{MAXIMUM RATINGS* (Voltages Referenced to VSS)}
Symbol
Parameter
Value
Unit
VDD DC Supply Voltage
– 0.5 to + 18.0
V
Vin, Vout Input or Output Voltage (DC or Transient) – 0.5 to VDD + 0.5 V
Iin, Iout Input or Output Current (DC or Transient),
± 10
mA
per Pin
PD Power Dissipation, per Package†
500
mW
Tstg Storage Temperature
– 65 to + 150
_C
TL
Lead Temperature (8–Second Soldering)
260
_C
* Maximum Ratings are those values beyond which damage to the device may occur.
†Temperature Derating:
Plastic “P and D/DW” Packages: – 7.0 mW/_C From 65_C To 125_C
Ceramic “L” Packages: – 12 mW/_C From 100_C To 125_C
LENGTH SELECT TRUTH TABLE
L32 L16 L8 L4 L2 L1 Register Length
000000
000001
000010
000011
000100
000101


















100000
100001


















111100
111111
111110
111101
1 Bit
2 Bits
3 Bits
4 Bits
5 Bits
6 Bits



33 Bits
34 Bits



61 Bits
62 Bits
63 Bits
64 Bits
NOTE: Length equals the sum of the binary length control
subscripts plus one.
REV 3
1/94
©MMOotoTrOolaR, IOncL. A199C5MOS LOGIC DATA
MC14557B
L SUFFIX
CERAMIC
CASE 620
P SUFFIX
PLASTIC
CASE 648
DW SUFFIX
SOIC
CASE 751G
ORDERING INFORMATION
MC14XXXBCP
MC14XXXBCL
MC14XXXBDW
Plastic
Ceramic
SOIC
TA = – 55° to 125°C for all packages.
BLOCK DIAGRAM
3
RESET
4
CLOCK
5
CE
6
B
Q
10
7
A
9
A/B SELECT
2
L1
1
L2
15
L4
Q
11
14
L8
13
L16
12
L32
VDD = PIN 16
VSS = PIN 8
TRUTH TABLE
Inputs
Output
Rst A/B Clock CE
Q
0
0
0
1
0
0
0
1
1
X
0
B
0
A
1
B
1
A
X
X
0
Q is the output of the first selected shift
register stage.
X = Don’t Care
MC14557B
1