Reliability Of Programmed Data - Renesas H8 Series Hardware Manual

Section 6 ROM
• Avoid touching the socket adapter or chip while programming, since this may cause contact
faults and write errors.
6.3.3

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 6.5 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 6.5 Recommended Screening Procedure
If a group of programming errors occurs while the same PROM programmer is in use, stop
programming and check the PROM programmer and socket adapter for defects, using a
microcomputer with on-chip EPROM in a windowed package, etc. Please inform Renesas
Technology of any abnormal conditions noted during or after programming or in screening of
program data after high-temperature baking.
Rev. 6.00 Sep 12, 2006 page 110 of 526
REJ09B0326-0600