18.3.2
Notes on Programming
(1) A PROM programmer that does not allow start address setting cannot be used. If such a
PROM programmer is used, it will not be possible to perform verification at addresses H'10002,
H'10003, H'10004, and so on. Therefore a PROM programmer that allows address setting must be
used.
(2) Program with the specified voltages and timing. The programming voltage (VPP) is
12.5 V.
Caution: Applied voltages in excess of the specified values can permanently destroy the chip. Be
particularly careful about the PROM programmer’s overshoot characteristics.
If the PROM programmer is set to HN27C101 specifications, VPP will be 12.5 V.
(3) Before writing data, check that the socket adapter and chip are correctly mounted in the
PROM writer. Overcurrent damage to the chip can result if the index marks on the PROM
programmer, socket adapter, and chip are not correctly aligned.
(4) Don’t touch the socket adapter or chip while writing. Touching either of these can cause
contact faults and write errors.
(5) Page programming is not supported. Do not select page programming mode.
(6) The H8/3337Y PROM size is 60 kbytes. The H8/3334Y PROM size is 32 kbytes. Set the
address range to H'0000 to H'F77F for the H8/3337Y, and to H'0000 to H'7FFF for the H8/3334Y.
When programming, specify H'FF data for unused address areas (H'F780 to H'1FFFF in the
H8/3337Y, H'8000 to H'1FFFF in the H8/3334Y).
18.3.3
Reliability of Programmed Data
An effective way to assure the data holding characteristics of the programmed chips is to bake
them at 150˚C, then screen them for data errors. This procedure quickly eliminates chips with
PROM memory cells prone to early failure.
Figure 18.7 shows the recommended screening procedure.
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RENESAS [ RENESAS TECHNOLOGY CORP ]
