Philips Semiconductors

Product specification

80C31/80C51/87C51

CMOS single-chip 8-bit microcontrollers

1996 Aug 16

14

AC ELECTRICAL CHARACTERISTICS FOR PHILIPS DEVICES

SYMBOL

FIGURE

PARAMETER

MIN

MAX

UNIT

Oscillator frequency:

Speed Versions

PCB8031/51

–2

PCA/PCB/PCF80C31/51

–3

PCB/PCF80C31/51

–4

PCB/FB80C31/51

–5

0.5

1.2

1.2

1.2

12

16

24

33

MHz

MHz

MHz

MHz

1

ALE pulse width

ns

1

Address valid to ALE low

ns

1

Address hold after ALE low

ns

1

ALE low to valid instruction in

ns

1

ALE low to PSEN low

ns

1

PSEN pulse width

ns

1

PSEN low to valid instruction in

ns

1

Input instruction hold after PSEN

0

ns

1

Input instruction float after PSEN

ns

1

Address to valid instruction in

ns

1

PSEN low to address float

10

ns

Data Memory

2, 3

RD pulse width

ns

2, 3

WR pulse width

ns

2, 3

RD low to valid data in

ns

2, 3

Data hold after RD

0

ns

2, 3

Data float after RD

ns

2, 3

ALE low to valid data in

ns

2, 3

Address to valid data in

ns

2, 3

ALE low to RD or WR low

ns

2, 3

Address valid to WR low or RD low

ns

2, 3

Data valid to WR transition

ns

2, 3

Data hold after WR

ns

2, 3

RD low to address float

0

ns

2, 3

RD or WR high to ALE high

ns

External Clock

5

High time

15

ns

5

Low time

15

ns

5

Rise time

20

ns

5

Fall time

20

ns

NOTES:

1. Parameters are valid over operating temperature range unless otherwise specified.

2. Load capacitance for port 0, ALE, and PSEN = 100pF, load capacitance for all other outputs = 80pF.

3. For all Philips speed versions only.

4. Interfacing the 80C31/51 to devices with float times up to 30ns is permitted. This limited bus contention will not cause damage to port 0

drivers.