Figure 18-30 Mode Transition Timing
(Example: Boot Mode
→
User Mode
↔
User Program Mode)
627
tosc1
12
±
0.6 V
0 to
Vcc V
2.7 to
5.5 V
V
ppE
set
Clear
VppE
User program mode
Mode
switch-
ing
*
1
Mode
switch-
ing
*
1
Boot mode
User program
mode
User
mode
User
mode
ø
V
CC
V
PP
MD2
to 0
RES
V
PP
E bit
0 to
Vcc V
t
MDS
12
±
0.6 V
min 0
µ
s
min 0
µ
s
min 10 ø
t
MDS
*
2
t
FRS
*
2
Programming/
erasing
possible
t
FRS
Programming/
erasing
possible
t
FRS
t
VPS
Programming/
erasing
possible
t
FRS
t
VPS
Programming/
erasing
possible
t
VPS
t
VPS
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)
1
2
Notes
When entering boot mode or making a transition from boot mode to another mode, mode switching must be carried
out by means of RES input. The pin output states change during this switchover interval (the interval during which
the RES pin is low), and therefore these pins should not be used as output signals during this time.
When making a transition from boot mode to another mode, the flash memory read setup time t
FRS
and
mode programming setup time t
MDS
must be satisfied with respect to RES clearance timing.
VppE
cleared
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