
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
V
CC
V
CC
V
CC
V
CC
Mode
Write
Verify
Programming inhibited
CE
Low
Low
Low
Low
High
High
OE
High
Low
Low
High
Low
High
PGM
Low
High
Low
High
Low
High
V
PP
V
PP
V
PP
V
PP
0
7
to 0
0
Data input
Data output
High-impedance
A
16
to A
0
Address input
Address input
Address input
Note:
The V
PP
and V
CC
pins must be held at the V
PP
and V
CC
voltage levels.
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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