Datasheet

699
22.6.1 Boot Mode
When boot mode is used, the flash memory programming control program must be prepared in the
host beforehand. The SCI to be used is set to channel asynchronous mode.
When a reset start is executed after the LSI pins have been set to boot mode in the power-on reset
state, the boot program built into the LSI is started and the programming control program prepared
in the host is serially transmitted to the LSI via SCI channel 1. In the LSI, the programming
control program received via SCI channel 1 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 22.8, and the boot mode execution
procedure in figure 22.9.
RXD1
TXD1
SCI1
Host
Write data reception
Verify data transmission
LSI
Flash memory
On-chip RAM
Figure 22.8 System Configuration in Boot Mode