HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 173

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

Notes: 1. Definitions of V
164
b. The V
pin. The threshold level is approximately in the range from V
When this flag is set, it becomes possible to write to the flash memory control register
(FLMCR) and the erase block registers (EBR1 and EBR2), even though the V
may not yet have reached the programming voltage range of 12.0 V 0.6 V.
Do not actually program or erase the flash memory until V
voltage range.
The programming voltage range for programming and erasing flash memory is 12.0 V 0.6
V (11.4 V to 12.6 V). Programming and erasing cannot be performed correctly outside this
range. When not programming or erasing the flash memory, insure that the V
does not exceed the V
2. The time depends on the resonator used; refer to the electrical characteristics.
— Oscillation must have stabilized (following the elapse of the oscillation settling
— The MCU must be in the reset state, or in a state in which reset has ended normally
— The P and E bits must be cleared in the flash memory control register (FLMCR).
— There must be no program runaway.
These power-on and power-off timing requirements for V
satisfied in the event of a power failure and in recovery from a power failure. If these
requirements are not satisfied, overprogramming or overerasing may occur due to
program runaway, etc., which could cause memory cells to malfunction.
Application: Raising the voltage from V
Release:
Cut-off:
PP
time) or be stopped.
When the V
oscillation settling time*
(reset has been released) and flash memory is not being accessed.
Apply or release V
memory (when a program in on-chip RAM or external memory is executing). Flash
memory data cannot be read normally at the instant when V
so do not read flash memory while V
For a reset during operation, apply or release V
held low for at least 10 system clock cycles (10ø).
When applying or releasing V
When V
timer.
flag is set and cleared by a threshold decision on the voltage applied to the FV
PP
Dropping the voltage from 12.0 V 0.6 V to V
Halting voltage application (floating state)
is applied, program execution must be supervised, e.g. by the watchdog
CC
PP
power is turned on, hold the RES pin low for the duration of the
CC
application, release, and cut-off are as follows:
voltage. This will prevent unintentional programming and erasing.
PP
either in the reset state, or when the CPU is not accessing flash
2
(t
rc
= 20 ms) before applying V
PP
, make sure that the P or E bit is not set by mistake.
PP
CC
is being applied or released.
to 12.0 V 0.6 V
PP
only after the RES pin has been
PP
has reached the programming
CC
CC
and V
+2 V to 11.4 V.
CC
PP
.
PP
is applied or released,
PP
should also be
PP
PP
voltage
voltage
PP