HD64F2357F20V Datasheet, PDF (606/1049 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-chip Microcomputer H8S Family / H8S/2300 Series

19.6.3 Flash Memory Operating Modes
Mode Transitions: When the mode pins and the FWE pin are set in the reset state and a reset-start is executed, the MCU
enters one of the operating modes shown in figure 19-8. In user mode, flash memory can be read but not programmed or
erased.
Flash memory can be programmed and erased in boot mode, user program mode, and programmer mode.
MD2 = MD1 = 1
Reset state
User mode with
on-chip ROM
enabled
FWE = 1
FWE = 0
RES = 0
RES = 0
User
program mode
RES = 0
*1
*2
RES = 0
Programmer
mode
On-board programming mode
Boot mode
Notes: Only make a transition between user mode and user program mode when the CPU is
not accessing the flash memory.
1. MD2 = MD1 = MD0 = 0, P66 = 1, P65 = P64 = 0
2. NMI = 1, FWE = 1, MD₂ = 0, MD₁ = 1
Figure 19-8 Flash Memory Mode Transitions
Rev.6.00 Oct.28.2004 page 576 of 1016
REJ09B0138-0600H