AT89LS53_14 Datasheet, PDF (1/3 Pages) ATMEL Corporation – 12K Bytes of In-System Reprogrammable Downloadable Flash Memory

This errata is applicable to the following devices:
• AT89S8252
• AT89LS8252
• AT89S53
• AT89LS53
with the following markings and needs to be used in conjunction with the correspond-
ing device datasheets.
AT89S8252
24XX
XXXX
AT89LS8252
12XX
XXXX
AT89S53
24XX
XXXX
AT89LS53
12XX
XXXX
Regarding the in-system programming procedure, ATMEL currently recommends the
following ISP waveforms for implementing the ISP programming algorithm in the
AT89S-series devices:
(V_CC should be powered up and stable PRIOR to the waveforms below)
V_CC
GND
A (<1/2 machine cycle)
RST
(>2 machine cycles)
(>1 machine cycle)
SCK
7
6
This glitch MAY occur in certain systems because when RST
goes high, port 1 pins will be driven with a strong pullup for
one clock cycle; if the glitch does occur, it can be interpreted
incorrectly as the first SCK pulse of a serial data stream.
So the falling edge of RST at point A is necessary to
“clean-up” the internal state machine.
Microcontrollers
AT89S8252
AT89LS8252
AT89S53
AT89LS53
Errata Sheet
These waveforms should be used in addition to the serial downloading waveforms
shown in the respective device datasheets.
Rev. 1486A–10/99
1