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