HD6475348R Datasheet, PDF (325/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

3. Don’t touch the socket adapter or chip while writing. Touching either of these can cause
contact faults and write errors.
17.4 H8/536 Programming
The write, verify, and other sub-modes of PROM mode are selected as shown in table 17-7.
Table 17-7 Selection of Sub-Modes in PROM Mode (H8/536)
Pins
Mode
CE OE PGM VPP VCC 07 to 00
Write
Low High Low VPP VCC Data input
Verify
Low Low High VPP VCC Data output
Programming inhibited Low Low Low VPP VCC High-impedance
Low High High
High Low Low
High High High
Note: The VPP and VCC pins must be held at the VPP and VCC voltage levels.
A16 to A0
Address input
Address input
Address input
Standard EPROM read/write specifications are used, the same as for the HN27C101. The
HN27C101 has two programming modes: page programming and byte programming.
The H8/536 does not support page programming, so select byte programming.
17.4.1 Writing and Verifying
An efficient, high-speed programming procedure can be used to write and verify PROM data. This
procedure writes data quickly without subjecting the chip to voltage stress and without sacrificing
data reliability. It leaves the data H'FF written in unused addresses.
Figure 17-6 shows the basic high-speed programming flowchart.
Tables 17-8 and 17-9 list the electrical characteristics of the chip during programming.
Figure 17-7 shows a timing diagram.
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