HD64F2168 Datasheet, PDF (718/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

(f) Operating Clock Frequency Inquiry
The boot program will return the number of operating clock frequencies, and the maximum and
minimum values.
Command H'23
• Command, H'23, (1 byte): Inquiry regarding operating clock frequencies
Response H'33
Size
Number of operating clock
frequencies
Minimum value of operating Maximum value of operating clock
clock frequency
frequency
···
SUM
• Response, H'33, (1 byte): Response to operating clock frequency inquiry
• Size (1 byte): The number of bytes that represents the minimum values, maximum values, and
the number of frequencies.
• Number of operating clock frequencies (1 byte): The number of supported operating clock
frequency types
(e.g. when there are two operating clock frequency types, which are the main and peripheral
clocks, the number of types will be H'02.)
• Minimum value of operating clock frequency (2 bytes): The minimum value of the multiplied
or divided clock frequency.
The minimum and maximum values represent the values in MHz, valid to the hundredths place
of MHz, and multiplied by 100. (e.g. when the value is 20.00 MHz, it will be 2000, which is
H'07D0.)
• Maximum value (2 bytes): Maximum value among the multiplied or divided clock frequencies.
There are as many pairs of minimum and maximum values as there are operating clock
frequencies.
• SUM (1 byte): Checksum
Rev. 3.00, 03/04, page 678 of 830