Boot Mode - Hitachi H8S/2338 Series Hardware Manual

17.6.1

Boot Mode

When boot mode is used, the flash memory programming control program must be prepared in the
host beforehand. The channel 1 SCI to be used is set to asynchronous mode.
When a reset-start is executed after the H8S/2338 Series, H8S/2328 Series, or H8S/2318 Series
chip's pins have been set to boot mode, the boot program built into the chip is started and the
programming control program prepared in the host is serially transmitted to the chip via the SCI.
In the chip, 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 17-9, and the boot program mode
execution procedure in figure 17-10.
Host
562
Write data reception
Verify data transmission
Figure 17-9 System Configuration in Boot Mode
H8S/2338 Series, H8S/2328 Series,
or H8S/2318 Series
Flash memory
RxD1
SCI1
TxD1
On-chip RAM