Intel mcs-48 manual Timing Specification for Programming, Vdol

8041 AJ8641 AJ8741 A

8741A Erasure Characteristics

The erasure characteristics of the 8741A are such that erasure begins to occur when exposed to light with wavelengths shorter than approximately 4000 Ang· stroms (A). It should be noted that sunlight and certain types of fluorescent lamps have wavelengths In the 3000-4000A range. Data show that constant exposure to room level fluorescent lighting could erase the typical 8741A in approximately 3 years while it would take ap· proximately one week to cause erasure when exposed to direct sunlight. If the 8741A is to be exposed to these types of lighting conditions for extended periods of time, opaque labels are available from Intel which

should be placed over the 8741A window to prevent unintentional erasure.

The recommended erasure procedure for the 8741A is exposure to shortwave ultraviolet light which has a wavelength of 2537A. The integrated dose (i.e., UV inten· sity x exposure time) for erasure should be a minimum of 15 w·sec/cm2. The erasure time with this dosage is approximately 15 to 20 minutes using an ultraviolet lamp with a 12,000 ,..W/cm 2 power rating. The 8741A should be placed within one inch of the lamp tubes duro ing erasure. Some lamps have a filter on their tubes which should be removed before erasure.

A.C. TIMING SPECIFICATION FOR PROGRAMMING

TA = 25°C ±5°C, Vcc = 5V ±5%, Voo = 25V ±1V

Symbol	Parameter
tAW	Address Setup Time to RESET t
tWA	Address Hold Time After RESET t
tow	Data in Setup Time to PROG I
two	Data in Hold Time After PROG I
tPH	RESET Hold Time to Verify
tvoow	Voo Setup Time to PROG t
tVOOH	Voo Hold Time After PROG I
tpw	Program Pulse Width
trw	Test 0 Setup Time for Program Mode
tWT	Test 0 Hold Time After Program Mode
too	Test 0 to Data Out Delay
tww	RESET Pulse Width to Latch Address
tr, tf	Voo and PROG Rise and Fall Times
tCY	CPU Operation Cycle Time
tRE	RESET Setup Time Before EA t.

Min.	Max.	Unit	Test Conditions
4tcy
4tcy
4tcy
4tcy
4tcy
4tcy
0
50	60	mS
4tcy
4tcy
	4tcy
4tcy
0.5	2.0	I-'S
5.0		I-'S
4tcy

Note: If TEST 0 is high, too can be triggered by RESET t.

D.C. SPECIFICATION FOR PROGRAMMING

TA = 25°C ±5°C, Vcc = 5V ±5%, Voo = 25V ±1V

Symbol	Parameter	Min.	Max.	Unit	Test Conditions
VOOH	Voo Program Voltage High ~evel	24.0	26.0	V
VDOL	VOD Voltage Low Level	4.75	5.25	V
VPH	PROG Program Voltage High Level	21.5	24.5	V
VpL	PROG Voltage Low Level		0.2	V
VEAH	EA Program or Verify Voltage High Level	21.5	24.5	V
VEAL	EA Voltage Low Level		5.25	V
100	VDD High Voltage Supply Current		30.0	mA
IPROG	PROG High Voltage Supply Current		16.0	mA
lEA	EA High Voltage Supply Current		1.0	mA

9-131 0018BA