HD64F2638F20J Datasheet, PDF (868/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 21B ROM
(H8S/2638 Group, H8S/2639 Group, H8S/2630 Group)
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
21B.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/2638’, H8S/2639’, and H8S/2630’ pins have been set
to boot mode, the boot program built into the H8S/2638, H8S/2639, and H8S/2630 are started and
the programming control program prepared in the host is serially transmitted to the H8S/2638,
H8S/2639, and H8S/2630 via the SCI. In the H8S/2638, H8S/2639, and H8S/2630, 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 21B-7, and the boot mode execution
procedure in figure 21B-8.
LSI
Flash memory
Host
Write data reception
Verify data transmission
RxD1
SCI1
TxD1
On-chip RAM
Figure 21B-7 System Configuration in Boot Mode
Page 818 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010