r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 1092

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 21 Flash Memory
21.9
Initiating boot mode enables the boot program to communicate with the host by using the on-chip
SCI_I. The serial communication interface specification is shown below.
(1)
The boot program has three states.
1. Bit-Rate-Adjustment State
2. Inquiry/Selection State
3. Programming/erasing state
Rev. 1.00 Sep. 19, 2008 Page 1064 of 1270
REJ09B0466-0100
In this state, the boot program adjusts the bit rate to communicate with the host. Initiating boot
mode enables starting of the boot program and entry to the bit-rate-adjustment state. The
program receives the command from the host to adjust the bit rate. After adjusting the bit rate,
the program enters the inquiry/selection state.
In this state, the boot program responds to inquiry commands from the host. The device name,
clock mode, and bit rate are selected. After selection of these settings, the program is made to
enter the programming/erasing state by the command for a transition to the
programming/erasing state. The program transfers the libraries required for erasure to the
RAM and erases the user MATs before the transition.
Programming and erasure by the boot program take place in this state. The boot program is
made to transfer the programming/erasing programs to the RAM by commands from the host.
Sum checks and blank checks are executed by sending these commands from the host.
Status
Serial Communication Interface Specification for Boot Mode