Writing And Verifying - Renesas H8 Series Hardware Manual

Section 6 ROM
6.3.1

Writing and Verifying

An efficient, high-speed, high-reliability method is available for writing and verifying the PROM
data. This method achieves high speed without voltage stress on the device and without lowering
the reliability of written data. Data in unused address areas has a value of H'FF. The basic flow of
this high-speed, high-reliability programming method is shown in figure 6.3.
No
Error
Figure 6.3 High-Speed, High-Reliability Programming Flow Chart
Rev. 6.00 Sep 12, 2006 page 106 of 526
REJ09B0326-0600
Set write/verify mode
V = 6.0 V ±0.25 V, V
CC
Yes
<
n 25
Write time t
NG
Write time t
Last address?
Set read mode
V = 5.0 V ±0.5 V, V
CC
NG
Start
= 12.5 V ±0.3 V
PP
Address = 0
n = 0
→
n + 1 n
= 0.2 ms ±5%
PW
Verify
OK
= 3n ms
OPW
No
Yes
= V
PP CC
Read all
addresses?
Yes
End
→
Address + 1 address