HD6473837H Datasheet, PDF (144/562 Pages) Renesas Technology Corp – Hardware Manual

6.6 Reliability of Programmed Data
A highly effective way of assuring data retention characteristics after programming is to screen the
chips by baking them at a temperature of 150°C. High-temperature baking is a screening method
that quickly eliminates PROM memory cells prone to initial data retention failure.
Figure 6.10 shows a flowchart of this screening procedure.
Write program and verify contents
Bake at high temperature with power off
125°C to 150°C, 24 hrs to 48 hrs
Read and check program
Install
Figure 6.10 Recommended Screening Procedure
If write errors occur repeatedly while the same PROM programmer is being used, stop
programming and check for problems in the PROM programmer and socket adapter, etc.
Please notify your Hitachi representative of any problems occurring during programming or in
screening after high-temperature baking.
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