TS80C51RA2 Atmel Corporation, TS80C51RA2 Datasheet - Page 54

• Manufacturer Part Number: TS80C51RA2
• Description: High Performance 8-bit Microcontroller
• Manufacturer: Atmel Corporation

Figure 19. Programming and Verification Signal’s Waveform
EPROM Erasure
(Windowed Packages
Only)
Erasure Characteristics
Signature Bytes
54
TS8xC51Rx2
Control signals
ALE/PROG
EA/VPP
A0-A12
D0-D7
12.75V
5V
0V
Erasing the EPROM erases the code array, the encryption array and the lock bits return-
ing the parts to full functionality.
Erasure leaves all the EPROM cells in a 1’s state (FF).
The recommended erasure procedure is exposure to ultraviolet light (at 2537 Å) to an
integrated dose at least 15 W-sec/cm
12,000 µW/cm
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 wave-
length 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.
The
61h. To read these bytes follow the procedure for EPROM verify but activate the control
lines provided in Table 31. for Read Signature Bytes. Table 33. shows the content of the
signature byte for the TS87C51RB2/RC2/RD2.
Table 33. Signature Bytes Content
Programming Cycle
TS83/87C51RB2/RC2/RD2
Location
Data In
30h
31h
60h
60h
60h
60h
60h
60h
61h
100µs
2
rating for 30 minutes, at a distance of about 25 mm, should be sufficient.
has four signature bytes in location 30h, 31h, 60h and
Contents
7Ch
FCh
BBh
58h
57h
37h
B7h
3Bh
FFh
Read/Verify Cycle
2
. Exposing the EPROM to an ultraviolet lamp of
Data Out
Comment
Manufacturer Code: Atmel
Family Code: C51 X2
Product name: TS83C51RD2
Product name: TS87C51RD2
Product name: TS83C51RC2
Product name: TS87C51RC2
Product name: TS83C51RB2
Product name: TS87C51RB2
Product revision number
4188A–8051–10/02