Intel mcs-48 manual Input Waveforms for A.C. Tests, BUS Parameters

8279, 8279-5

A.C. CHARACTERISTICS

TA = O°C to 70°C, VSS = OV, (Note 1)

BUS PARAMETERS

READ CYCLE:

		8279			8279·5
Symbol	Parameter	Min.	Max.	Min.	Max.	Unit
tAR	Address Stable Before READ	50		0		ns
tRA	Address Hold Time for READ	5		0		ns
tRR	READ Pulse Width	420		250		ns
tRol21	Data Delay from READ		300		150	ns
tAO[21	Address to Data Valid		450		250	ns
tOF	READ to Data Floating	10	100	10	100	ns
tRCY	Read Cycle Ti me	1		1		IlS
WRITE CYCLE:
		8279			8279·5
Symbol	Parameter	Min.	Max.	Min.	Max.	Unit
tAW	Address Stable Before WR ITE	50		0		ns
tWA	Address Hold Time for WR ITE	20		0		ns
tww	WR ITE Pulse Width	400		250		ns
tow	Data Set Up Time for WR ITE	300		150		ns
two	Data Hold Time for WR ITE	40		0		ns

Notes:

1.8279, VCC = +5V ±5%; 8279·5, VCC = +5V ±10%.

2.8279, CL = 100pF; 8279-5, CL = 150pF.

OTHER TIMINGS:
			8279	8279·5
Symbol	Parameter	Min.	Max.	Min.	Max.	Unit
t¢w	Clock Pu Ise Width	230		120		nsec
tCY	Clock Period	500		320		nsec

Keyboard Scan Time:	5.1 msec	Digit·on Time:	480llsec
Keyboard Debounce Time:	10.3 msec	Blanking Time:	160llsec
Key Scan Time:	80llsec	Internal Clock Cycle:	10 11 sec
Display Scan Time:	10.3 msec

INPUT WAVEFORMS FOR A.C. TESTS:

u=x2.0 ?TEST POINTS <2.0 x=

O.BO.B

tI.4ti

9-79 AFN-00742A-10