Designing Boards with Atmel AT89C51, AT89C52, AT89C1051, and AT89C2051 for Writing Flash at In-Circuit Test:Recent improvements in chips and
testers have made it possible for the
tester to begin taking over the role traditionally
assigned to the PROM programmer.
Instead of having a PROM programmer
write nonvolatile memories
before assembling the board, the in-circuit
tester writes them during in-circuit
testing operations. Many Teradyne Z18-
series testers are now in use loading
code into nonvolatile memories, microcontrollers
and in-circuit programmable logic devices. The purpose of this note is to explain how the Z18 approaches the writing task for Atmel AT89C series IC’s,so that designers of boards using these chips can get the best results.