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.
To write the flash memories embedded in the Atmel AT89C series chips, the Z18-family tester must be equipped with the Digital Function Processor (DFP) option.