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

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