HD6475348R Datasheet, PDF (324/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

Address
Data
VPP
VPP
VCC
VCC ⁺¹
VCC
VCC
CE
OE
Write
tAS
Input data
tDS
tDH
tVPS
tVCS
tPW
tOES
Verify
tAH
Output data
tDF
tOE
Figure 17-5 PROM Write/Verify Timing (H8/534)
17.3.2 Notes on Writing
1. Write with the specified voltages and timing. The programming voltage (VPP) in the
PROM mode is 12.5 V.
Caution: Applied voltages in excess of the specified values can permanently destroy to the chip.
Be particularly careful about the PROM writer’s overshoot characteristics.
If the PROM writer is set to Intel specifications or Hitachi HN27256 or HN27C256 specifications,
Vpp will be 12.5 V.
2. 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
writer, socket adapter, and chip are not correctly aligned.
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