R01UH0823EJ0100 Rev.1.00
Page 1718 of 1823
Jul 31, 2019
RX23W Group
50. Flash Memory (FLASH)
50.10.6.2
Operating Frequency Select
This command is used to specify the operating frequency of the MCU and a bit rate for communication with the flash
memory programmer. The bit rate selected in this command should be set to a value with error of less than 4% compared
to the bit rate obtained by dividing 32 or 8 MHz that corresponds to the operating voltage.
If the specified settings can be supported, the MCU sends a response (06h). If the bit rate error is 4% or more or the SUM
of the received command does not match, the MCU sends an error response.
After the host receives a response, wait for at least a 1-bit period at the old bit rate, and send communication
confirmation data at the new bit rate.
If the MCU successfully receives communication confirmation data, the MCU sends a response (06h). If the MCU fails
to receive the communication confirmation data, the MCU sends an error response.
Size (1 byte): Total bytes of data of Bit rate, Dummy data, Number of clocks, and Multiplier (the value is always 07h)
Bit rate (2 bytes): New bit rate
The value is calculated by dividing the bit rate by 100 (Example: Set 00C0h for 19200 bps)
Dummy data (2 bytes): The value should always be set to 0000h
Number of clocks (1 byte): Types of clocks for multiplier setting (the value is always 02h)
Multiplier 1 (1 byte): Multiplier of the system clock (ICLK) (the value is always 01h)
Multiplier 2 (1 byte): Multiplier of the peripheral module clock (PCLK) (the value is always 01h)
SUM (1 byte): Value that is calculated so the sum of command data including dummy data is 00h
Error (1 byte): Error code
11h: SUM error
24h: Bit rate selection error
Command
3Fh
Size
Bit rate
Dummy data
Number of
clocks
Multiplier 1
Multiplier 2
SUM
Response
06h
Error response
BFh
Error
Communication
confirmation
06h
Response
06h
Error response
FFh