HD643303x Hitachi, HD643303x Datasheet - Page 418

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

14.4 Reliability of Programmed Data
A highly effective way to improve data retention characteristics is to bake the programmed chips at
150°C, then screen them for data errors. This procedure quickly eliminates chips with PROM
memory cells prone to early failure.
Figure 14-6 shows the recommended screening procedure.
Program chip and verify programmed data
Bake chip for 24 to 48 hours at
125°C to 150°C with power off
Read and check program
Install
Figure 14-6 Recommended Screening Procedure
If a series of programming errors occurs while the same PROM programmer is in use, stop
programming and check the PROM programmer and socket adapter for defects. Please inform
Hitachi of any abnormal conditions noted during or after programming or in screening of program
data after high-temperature baking.
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