Intel 83C51FA, 80C51FA Explanation Of The Ac Symbols, External Memory Characteristics

Models: 80C51FA 83C51FA

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EXPLANATION OF THE AC SYMBOLS

AUTOMOTIVE 80C51FA/83C51FA

EXPLANATION OF THE AC SYMBOLS

Each timing symbol has 5 characters. The first char- acter is always a `T' (stands for time). The other characters, depending on their positions, stand for the name of a signal or the logical status of that signal. The following is a list of all the characters and what they stand for.

A:Address

C:Clock

D:Input Data

H:Logic level HIGH

I:Instruction (program memory contents)

L:Logic level LOW, or ALE

P:PSEN

Q:Output Data

R:RD signal

T:Time

V:Valid

W:WR signal

X:No longer a valid logic level

Z:Float

For example,

TAVLL e Time from Address Valid to ALE Low TLLPL e Time from ALE Low to PSEN Low

AC CHARACTERISTICS (TA e b40§C to a125§C, VCC e 5V g10%, VSS e 0V, Load Capacitance for Port 0, ALE/PROG and PSEN e 100 pF, Load Capacitance for All Other Outputs e 80 pF)

EXTERNAL MEMORY CHARACTERISTICS

Symbol

 

 

 

 

 

 

 

 

Parameter

12 MHz Oscillator

Variable Oscillator

Units

 

 

 

 

 

 

 

 

Min

Max

Min

Max

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1/T CLCL

Oscillator Frequency

 

 

3.5

16

MHz

TLHLL

ALE Pulse Width

127

 

2TCLCLb40

 

ns

TAVLL

Address Valid to ALE Low

43

 

TCLCLb40

 

ns

TLLAX

Address Hold After ALE Low

53

 

TCLCLb30

 

ns

TLLIV

ALE Low to Valid Instruction In

 

224

 

4TCLCLb110

ns

TLLPL

ALE Low to

 

 

 

 

 

 

 

 

 

 

Low

53

 

TCLCLb30

 

ns

PSEN

 

 

TPLPH

 

 

 

 

 

 

 

Pulse Width

205

 

3TCLCLb45

 

ns

PSEN

 

 

TPLIV

 

 

 

 

 

 

 

Low to Valid Instruction In

 

135

 

3TCLCLb115

ns

PSEN

 

 

TPXIX

Input Instr Hold After

 

 

 

 

 

 

Trans

0

 

0

 

ns

PSEN

 

 

TPXIZ

Input Instr Float After

 

 

 

Trans

 

59

 

TCLCLb25

ns

PSEN

 

 

TAVIV

Address to Valid Instruction In

 

302

 

5TCLCLb115

ns

TPLAZ

 

 

 

 

 

 

 

Low to Address Float

 

10

 

10

ns

PSEN

 

 

TRLRH

 

 

 

 

Pulse Width

400

 

6TCLCLb100

 

ns

RD

 

 

TWLWH

 

 

Pulse Width

400

 

6TCLCLb100

 

ns

WR

 

 

TRLDV

 

 

Low to Valid Data In

 

242

 

5TCLCLb175

ns

RD

 

 

TRHDX

Data Hold After

 

 

 

 

 

 

 

High

b10

 

b10

 

ns

RD

 

 

TRHDZ

Data Float After

 

 

 

 

 

High

 

107

 

2TCLCLb60

ns

RD

 

 

TLLDV

ALE Low to Valid Data In

 

507

 

8TCLCLb160

ns

TAVDV

Address Valid to Valid Data In

 

575

 

9TCLCLb175

ns

TLLWL

ALE Low to

 

 

 

 

or

 

 

 

Low

200

300

3TCLCLb50

3TCLCLa50

ns

RD

WR

TAVWL

Data Valid to

 

 

 

Low

203

 

4TCLCLb130

 

ns

WR

 

 

TQVWX

Address Valid before

 

Low

23

 

TCLCLb50

 

ns

WR

 

 

TWHQX

Data Hold after

 

 

High

33

 

TCLCLb50

 

ns

WR

 

 

TQVWH

Data Valid to

 

High

433

 

7TCLCLb150

 

ns

WE

 

 

TRLAZ

 

 

Low to Address Float

 

0

 

0

ns

RD

 

 

TWHLH

 

 

or

 

High to ALE High

43

123

TCLCLb40

TCLCLa40

ns

RD

WR

10

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Intel 83C51FA, 80C51FA specifications Explanation Of The Ac Symbols, External Memory Characteristics