HD64F2638F20J Datasheet, PDF (922/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 21C ROM
(H8S/2635 Group)
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
21C.8.1 Boot Mode
When boot mode is used, the flash memory programming control program must be prepared in the
host beforehand. The SCI channel to be used is set to asynchronous mode.
When a reset-start is executed after the H8S/2635 Group’s pins have been set to boot mode, the
boot program built into the H8S/2635 Group are started and the programming control program
prepared in the host is serially transmitted to the H8S/2635 Group via the SCI. In the H8S/2635
Group, the programming control program received via the SCI is written into the programming
control program area in on-chip RAM. After the transfer is completed, control branches to the start
address of the programming control program area and the programming control program execution
state is entered (flash memory programming is performed).
The transferred programming control program must therefore include coding that follows the
programming algorithm given later.
The system configuration in boot mode is shown in figure 21C-7, and the boot mode execution
procedure in figure 21C-8.
LSI
Flash memory
Host
Write data reception
Verify data transmission
RxD1
SCI1
TxD1
On-chip RAM
Figure 21C-7 System Configuration in Boot Mode
Page 872 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010