Renesas H8S/2319 series Hardware Manual page 641

φ
t
OSC1
V
CC
FWE
MD2 to MD0
t
RES
SWE
set
SWE bit
Mode
change
Period during which flash memory access is prohibited
(x: Wait time after setting SWE bit)
Period during which flash memory can be programmed
(Execution of program in flash memory prohibited, and data reads other than verify operations prohibited)
Notes: 1. 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 state of ports with multiplexed address functions and bus control
output pins (AS, RD, WR) will change during this switchover interval (the interval during which the RES pin
input is low), and therefore these pins should not be used as output signals during this time.
2. When making a transition from boot mode to another mode, a mode programming setup time t
ns is necessary with respect to RES clearance timing.
3. See section 20.3.6, Flash Memory Characteristics.
(Example: Boot Mode → → → → User Mode ↔
Min 0 µs
t
MDS
t
MDS
MDS
t
RESW
SWE
cleared
Boot Mode
*1
mode change
*3
Figure 17-32 Mode Transition Timing
*2
User User program mode
*1
mode
↔ User Program Mode)
↔ ↔
Rev. 5.00, 12/03, page 611 of 1088
User User program
mode mode
(min) of 200
MDS