HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 118

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

6.3.1
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 6.4.
Writing and Verifying
Error
Figure 6.4 High-Speed, High-Reliability Programming Flow Chart
No
n 25
Yes
V
No Go
CC
No Go
= 6.0 V
V
CC
Write time t
Write time t
= 5.0 V
Set write/verify mode
Set read mode
0.25 V, V
Last address?
Address = 0
addresses?
n + 1
Read all
PW
Verify
n = 0
Start
End
0.5 V, V
OPW
= 0.2 ms 5%
Yes
Go
Go
PP
n
= 3n ms
= 12.5 V
PP
= V
CC
No
0.3 V
Address + 1
address
109