p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 569

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

• 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
• 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
• Bit rate (2 bytes): New bit rate
• Input frequency (2 bytes): Frequency of the clock input to the boot program.
• Number of division ratios (1 byte): The number of supported division ratios.
• Division ratio 1 (1 byte): The division ratio for the main operating frequency
• Division ratio 2 (1 byte): The division ratio for the peripheral module operating frequency
• SUM (1 byte): Checksum
Response
• Response, H'06 (1 byte): Response to selection of a new bit rate.
Error Response
• Error response, H'BF (1 byte): Error response to selection of a new bit rate
division ratios, and division ratios
One hundredth of the value (e.g. when the value is 19200 bps, it will be 192, which is H'00C0.)
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)
Normally the number is two: one for the main operating frequency and one for peripheral
module operating frequency.
 Division ratio: The inverse of the division ratio, i.e. a negative number (e.g. when the clock
 Division ratio: The inverse of the division ratio, i.e. a negative number (e.g. when the clock
The boot program will return ACK when the new bit rate can be set.
is divided by two, the value will be H'FE[−2])
is divided by two, the value will be H'FE[−2])
Number of division
ratios
SUM
H'06
H'3F
H'BF
ERROR
Size
Division ratio 1 Division ratio 2
Section 19 Flash Memory (0.18-µm F-ZTAT Version)
Bit rate
Rev. 1.00 Sep. 21, 2006 Page 531 of 658
Input frequency
REJ09B0310-0100