8253/8253·5

A.C. CHARACTERISTICS TA = o°c to 70°C; Vcc = 5.0V ±5%; GND = OV

Bus Parameters (Note 1)

Re.dCycle:

SYMBOL

PARAMETER

tAR

Address Stable Before READ

tRA

Address Hold Time for READ

tRR

READ Pulse Width

tRO

Data Delay From READI21

tOF

READ to Data Floating

tRV

Recovery Time Between READ

 

and Any Other Control Signal

 

8253

 

8253-5

 

MIN.

MAX.

MIN.

MAX.

UNIT

50

 

30

 

ns

5

 

5

 

ns

400

 

300

 

ns

 

300

 

200

ns

25

125

25

100

ns

1

 

1

 

/-IS

Write Cycle:

 

 

 

 

8253

 

8253-5

 

SYMBOL

PARAMETER

 

MIN.

MAX.

MIN.

MAX,

UNIT

tAW

Address Stable Before WR ITE

 

50

 

30

 

ns

tWA

Address Hold Time for WR ITE

 

30

 

30

 

ns

tww

WR ITE Pulse Width

 

400

 

300

 

ns

tow

Data Set Up Time for WR ITE

 

300

 

250

 

ns

two

Data Hold Time for WR ITE

 

40

 

30

 

ns

tRv

Recovery Time Between WRITE

1

 

1

 

IlS

 

 

 

 

 

 

and Any Other Control Signal

 

 

 

 

 

 

Notes: 1. AC timings measured at VOH = 2.2. VOL = 0.8

 

 

 

 

 

 

2. Test Conditions: 8253. CL = 1OOpF; 8253-5: CL = 150pF.

 

 

 

 

 

Write Timing:

 

 

Read Timing:

 

 

 

Ao-t.CS__"1'__________t--f"'-

_

 

 

 

 

 

DATA BUS

Input Waveforms for A.C. Tests:

0.45 ---..I

>TEST POINTS

<::X___

2 . 4 -- ..... , . X

 

2,.28

 

_ _0

 

9-15

AFN-0074SA-tO

Page 330
Image 330
Intel mcs-48 manual Bus Parameters Note, Input Waveforms for A.C. Tests, Re.dCycle, Write Timing