HD64F3028F25 Datasheet, PDF (653/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

φ
V_CC
FWE
t_OSC1
t_MDS
Min 0µs
t_MDS^*2
MD₂ to MD₀
RES
t_MDS
t_RESW
SWE bit
SWE set
SWE
cleared
Mode
change^*1
Boot
mode
Mode User User program mode
change^*1 mode
User User program
mode mode
Period during which flash memory access is prohibited
(x: Wait time after setting SWE bit, y: Wait time after clearing SWE bit)^*3
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.
2.
3.
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
(CSn, 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.
When making a transition from boot mode to another mode, the mode programming setup time t_MDS must be
satisfied with respect to RES clearance timing.
See section 21.2.6, Flash Memory Characteristics.
Figure 18.18 Mode Transition Timing
(Example: Boot Mode → User Mode ↔ User Program Mode)
Rev. 2.00, 09/03, page 621 of 890