Renesas H8SX/1520 Series Hardware Manual page 680

Section 17 Flash Memory (0.18-(m F-ZTAT Version)
(k) New Bit-Rate Selection
The boot program will set a new bit rate and return the new bit rate.
This selection should be sent after sending the clock mode selection command.
Command H'3F
Number of
multiplication ratios
SUM
• Command, H'3F, (one byte): Selection of new bit rate
• Size (one byte): The number of bytes that represents the bit rate, input frequency, number of
multiplication ratios, and multiplication ratio
• Bit rate (two 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 (two bytes): Frequency of the clock input to the boot program
This is valid to the hundredths place and represents the value in MHz multiplied by 100. (E.g.
when the value is 20.00 MHz, it will be 2000, which is H'07D0.)
• Number of multiplication ratios (one byte): The number of multiplication ratios to which the
device can be set.
• Multiplication ratio 1 (one byte) : The value of multiplication or division ratios for the main
operating frequency
Multiplication ratio (one byte): The value of the multiplication ratio (e.g. when the clock
frequency is multiplied by four, the multiplication ratio will be H'04.)
Division ratio: The inverse of the division ratio, as a negative number (e.g. when the clock
frequency is divided by two, the value of division ratio will be H'FE. H'FE = D'-2)
• Multiplication ratio 2 (one byte): The value of multiplication or division ratios for the
peripheral frequency
Multiplication ratio (one byte): The value of the multiplication ratio (e.g. when the clock
frequency is multiplied by four, the multiplication ratio will be H'04.)
(Division ratio: The inverse of the division ratio, as a negative number (E.g. when the clock is
divided by two, the value of division ratio will be H'FE. H'FE = D'-2)
• SUM (one byte): Checksum
Response H'06
• Response, H'06, (one byte): Response to selection of a new bit rate
When it is possible to set the bit rate, the response will be ACK.
Rev. 3.00 Mar. 14, 2006 Page 642 of 804
REJ09B0104-0300
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Size Bit rate
Multiplication Multiplication
ratio 1 ratio 2
Input frequency