HD64F2638F20J Datasheet, PDF (799/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 21A ROM
(H8S/2636 Group)
21A.4.3 Mode Transitions
When the mode pins and the FWE pin are set in the reset state and a reset-start is executed, the
microcomputer enters an operating mode as shown in figure 21A-3. In user mode, flash memory
can be read but not programmed or erased.
The boot, user program and programmer modes are provided as modes to write and erase the flash
memory.
MD1 = 1,
MD2 = 1,
FWE = 0
*1
User mode
(on-chip ROM
enabled)
RES = 0
MD1 = 1,
MD2 = 1,
FWE = 1
FWE = 1 FWE = 0
User
*1
program mode
Reset state
RES = 0
MD2 = 0,
MD1 = 1,
FWE = 1
*2
RES = 0
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. RAM emulation possible
2. This LSI transits to programmer mode by using the dedicated PROM programmer.
Figure 21A-3 Flash Memory State Transitions
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 749 of 1458