Datasheet

Section 21 ROM (Mask ROM Version, H8S/2138 F-ZTAT, H8S/2134 F-ZTAT, and H8S/2132 F-ZTAT)
Rev. 4.00 Jun 06, 2006 page 582 of 1004
REJ09B0301-0400
21.4.3 Flash Memory Operating Modes
Mode Transitions: When the mode pins are set in the reset state and a reset-start is executed, the
MCU enters one of the operating modes shown in figure 21.3. 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.
Boot mode
On-board programming mode
User
program mode
User mode with
on-chip ROM
enabled
Reset state
Programmer
mode
RES = 0
SWE = 1
SWE = 0
*
1
*
2
Notes: Only make a transition between user mode and user program mode when the CPU is
not accessing the flash memory.
1. MD1 = MD0 = 0, P92 = P91 = P90 = 1
2. MD1 = MD0 = 0, P92 = 0, P91 = P90 = 1
RES = 0
RES = 0
RES = 0
MD1 = 1
Figure 21.3 Flash Memory Mode Transitions