(b) The V
PP
bit in the flash memory control register (FLMCR) is set or cleared when the V
PP
E
bit in FLMCR is set or cleared while a voltage of 12.0 ± 0.6 V is being applied to the V
PP
pin.
After the V
PP
E bit is set, it becomes possible to write the erase block registers (EBR1 and EBR2)
and the EV, PV, E, and P bits in FLMCR. Accordingly, program or erase flash memory 5 to 10 µs
after the V
PP
E bit is set. V
PP
should be turned off only when the P, E and V
PP
E bits in FLMCR
are cleared. Be sure that these bits are not set by mistaken access to FLMCR.
Figure 18-28 Power-On and Power-Off Timing (Boot Mode)
tosc1
12
±
0.6 V
min 0
µ
s
t
MDS
min 0
µ
s
12
±
0.6 V
0 to Vcc V
0 to Vcc V
2.7 to 5.5 V
VppE
set
VppE
cleared
min 10 ø
min 0
µ
s
0 to Vcc V
0 to Vcc V
t
FRS
t
VPS
*
ø
V
CC
V
PP
MD2
RES
V
PP
E bit
Programming/
erasing
possible
Period during which flash memory access is prohibited
Period during which flash memory can be rewritten
(Execution of program in flash memory prohibited, and data reads other than verify
operations prohibited)
*
t
VPS
: 5 to 10
µ
s
625
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