Philips Semiconductors

Product specification

74F821/822/823/824/825/826

Bus interface registers

1996 Jan 05

9

LOGIC DIAGRAM FOR 74F826

GND = Pin 12

D0

D

R

Q

Q0

D1

Q1

3

22

D2

Q2

4

21

D3

Q3

5

20

D4

Q4

6

19

D5

Q5

7

18

D6

Q6

8

17

D7

Q7

9

16

10

15

CP

CE

14

11

MR

1

OE0

SF00505A

13

CP

2

23

OE1

OE2

D

R

Q

CP

D

R

Q

CP

D

R

Q

CP

D

R

Q

CP

D

R

Q

CP

D

R

Q

CP

D

R

Q

CP

FUNCTION TABLE FOR 74F825 AND 74F826

INPUTS

OUTPUTS

INPUTS

74F825

74F826

OPERATING MODE

OEn

MR

CE*

CP

Dn

Q

Q

L

L

X

X

X

L

L

Clear

L

H

L

↑

h

H

L

Load and read data

L

H

L

↑

l

L

H

Load and read data

L

H

H

X

X

NC

NC

Hold

H

X

X

X

X

Z

Z

High impedance

H = High-voltage level

h

= High state must be present one setup time before the low-to-high clock transition

L

= Low-voltage level

l

= Low state must be present one setup time before the low-to-high clock transition

NC= No change

X = Don’t care

Z = High impedance “off” state

*

= Since CE input is sensitive to very short (<3ns) high-to-low-to-high going spikes while CP is high, users should avoid the use of decoders

or other potentially glitch prone device on the CE input.

↑ = Low-to-high clock transition

ABSOLUTE MAXIMUM RATINGS

(Operation beyond the limit 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

PARAMETER

RATING

UNIT

Supply voltage

–0.5 to +7.0

V

Input voltage

–0.5 to +7.0

V

Input current

–30 to +5

mA

Voltage applied to output in high output state

V

Current applied to output in low output state

128

mA

T

Operating free air temperature range

Commercial range

0 to +70

°C

Operating free-air temperature range

Industrial range

–40 to +85

°C

Storage temperature range

–65 to +150

°C