TS83C51RB2-VCJD View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

TS83C51RB2-VCJD

High Performance 8-bit Microcontrollers

Atmel Corporation 

TS80C51RA2/RD2

TS83C51RB2/RC2/RD2

TS87C51RB2/RC2/RD2

A0-A12

Programming Cycle

Read/Verify Cycle

D0-D7

ALE/PROG

12.75V

EA/VPP 5V

0V

Control sig-

nals

Data In

100µs

Data Out

Figure 19. Programming and Verification Signal’s Waveform

8.4. EPROM Erasure (Windowed Packages Only)

Erasing the EPROM erases the code array, the encryption array and the lock bits returning the parts to full

functionality.

Erasure leaves all the EPROM cells in a 1’s state (FF).

8.4.1. Erasure Characteristics

The recommended erasure procedure is exposure to ultraviolet light (at 2537 Å) to an integrated dose at least 15

W-sec/cm2. Exposing the EPROM to an ultraviolet lamp of 12,000 µW/cm2 rating for 30 minutes, at a distance

of about 25 mm, should be sufficient. An exposure of 1 hour is recommended with most of standard erasers.

Erasure of the EPROM begins to occur when the chip is exposed to light with wavelength shorter than approximately

4,000 Å. Since sunlight and fluorescent lighting have wavelengths in this range, exposure to these light sources

over an extended time (about 1 week in sunlight, or 3 years in room-level fluorescent lighting) could cause

inadvertent erasure. If an application subjects the device to this type of exposure, it is suggested that an opaque

label be placed over the window.

Rev. C - 06 March, 2001

55

Share Link: