Philips Semiconductors
16-bit even/odd parity
generator/checker
Product specification
74HC/HCT7080
FEATURES
• Word-length easily expanded by cascading
• Generates either even or odd parity for 16-data bits
• Output capability: standard
• ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT7080 are high-speed Si-gate CMOS
devices. They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT7080 are 16-bit parity generators or
checkers commonly used to detect errors in high-speed
data transmission or data retrieval systems.
The even and odd parity output is available for generating
or checking even/odd parity up to 16-bits.
The even/odd parity output (E/O) is HIGH when an even
number of data inputs (I0 to I15) are HIGH and the
cascade/even-odd-changing input (X) is HIGH.
Expansion to larger word sizes is accomplished by
connecting the even/odd parity output (E/O) to the
cascade/even-odd-changing input (X) of the final stage.
QUICK REFERENCE DATA
GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns
SYMBOL PARAMETER
CONDITIONS
tPHL/ tPLH
CI
CPD
propagation delay
In to E/O
X to E/O
input capacitance
power dissipation capacitance per package
CL = 15 pF; VCC = 5 V
notes 1 and 2
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW):
PD = CPD × 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
TYPICAL
UNIT
HC HCT
29 32 ns
12 15 ns
3.5 3.5 pF
24 25 pF
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
December 1990
2