Datasheet
Section 7 ROM
REJ09B0465-0300 Rev. 3.00 Page 185 of 982
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
(f) Operating-Frequency Inquiry
In response to an operating-frequency inquiry command, the boot program returns the number of
operating frequency types and the respective maximum and minimum frequencies.
Command H'23
• Command H'23 (1 byte): Operating-frequency inquiry
Response H'33 Size Number of
operating
frequencies
Minimum operating
frequency
Maximum operating
frequency
…
SUM
• Response H'33 (1 byte): Response to an operating-frequency inquiry command
• Size (1 byte): The total size of the number-of-operating-frequencies, maximum-frequency, and
minimum-frequency fields.
• Number of operating frequencies (1 byte): The number of operating frequency types required
for the device
(For example, the value is H'02 if the main and peripheral module operating frequencies are
required.)
• Minimum operating frequency (2 bytes): The minimum frequency of a frequency-multiplied or
divided clock signal
The values in the minimum- and maximum-operating-frequency fields are obtained by
multiplying the operating frequency (MHz; to the second decimal place) by 100. (For example,
when the frequency is 20.00 MHz, 20.00 is multiplied by 100 to be 2000, and so H'07D0 is
returned here.)
• Maximum operating frequency (2 bytes): The maximum frequency of a frequency-multiplied
or divided clock signal.
As many pairs of the minimum- and maximum-operating-frequency fields are continued as the
number of operating frequencies (= number of operating frequency types).
• SUM (1 byte): Checksum