Renesas H8S Series Hardware Manual page 857

• SUM (1 byte): Checksum
(k) New Bit Rate Selection
The boot program will set a new bit rate in response to the new bit rate selection command, and
return the new bit rate in response to the confirmation.
This new bit rate selection command should be sent after sending the clock mode selection
command.
Command H'3F
Number of division
ratios
SUM
• Command, H'3F (1 byte): Selection of new bit rate
• Size (1 byte): The amount of data that represents the bit rate, input frequency, number of
division ratios, and division ratios
• Bit rate (2 bytes): New bit rate
One hundredth of the value (e.g. when the value is 19200 bps, it will be 192, which is H'00C0.)
• Input frequency (2 bytes): Frequency of the clock input to the boot program.
This is valid to the hundredths place and represents the frequency value (MHz) multiplied by
100. (e.g. when the value is 20.00 MHz, it will be 2000, which is H'07D0)
• Number of division ratios (1 byte): The number of supported division ratios.
Normally the number is two: one for the main operating frequency and one for peripheral
module operating frequency.
• Division ratio 1 (1 byte): The division ratio for the main operating frequency
 Division ratio: The inverse of the division ratio, i.e. a negative number (e.g. when the clock
is divided by two, the value will be H'FE[−2])
• Division ratio 2 (1 byte): The division ratio for the peripheral module operating frequency
 Division ratio: The inverse of the division ratio, i.e. a negative number (e.g. when the clock
is divided by two, the value will be H'FE[−2])
• SUM (1 byte): Checksum
Response H'06
• Response, H'06 (1 byte): Response to selection of a new bit rate.
The boot program will return ACK when the new bit rate can be set.
Error Response H'BF
• Error response, H'BF (1 byte): Error response to selection of a new bit rate
Size
Division ratio 1 Division ratio 2
ERROR
Section 21 Flash Memory (0.18-µm F-ZTAT Version)
Bit rate
Rev. 3.00 Jul. 14, 2005 Page 809 of 986
Input frequency
REJ09B0098-0300