HD6433802H Datasheet, PDF (144/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

6.3.2 Programming Precautions
• Use the specified programming voltage and timing.
The programming voltage in PROM mode (V_PP) is 12.5 V. Use of a higher voltage can
permanently damage the chip. Be especially careful with respect to PROM programmer
overshoot.
Setting the PROM programmer to Hitachi specifications for the HN27C101 will result in
correct V_PP of 12.5 V.
• Make sure the index marks on the PROM programmer socket, socket adapter, and chip are
properly aligned. If they are not, the chip may be destroyed by excessive current flow. Before
programming, be sure that the chip is properly mounted in the PROM programmer.
• Avoid touching the socket adapter or chip while programming, since this may cause contact
faults and write errors.
• Take care when setting the programming mode, as page programming is not supported.
• When programming with a PROM programmer, be sure to specify addresses from H'0000 to
H'3FFF. If programming is inadvertently performed from H'4000 onward, it may not be
possible to continue PROM programming and verification. When programming, H'FF should
be set as the data in address area H'4000 to H'1FFFF.
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