H8SX1638 Datasheet, PDF (910/1164 Pages) Renesas Technology Corp – Renesas 32-Bit CISC Microcomputer H8SX Family / H8SX/1600 Series

Section 22 Flash Memory
(e) Multiplication Ratio Inquiry
The boot program will return the supported multiplication and division ratios.
Command H'22
• Command, H'22, (one byte): Inquiry regarding multiplication ratio
Response H'32
Size
Number
of types
of
multipli
cation
Number of
Multiplica- ···
multiplication ratios tion ratio
···
SUM
• Response, H'32, (one byte): Response to the multiplication ratio inquiry
• Size (one byte): The amount of data that represents the numbers of types of multiplication, the
number of multiplication ratios, and the multiplication ratios
• Number of types of multiplication (one byte): The number of types of multiplication ratios to
which the device can be set.
(e.g. when there are two multiplied clock types, which are the main and peripheral clocks, the
number of types will be H'02.)
• Number of multiplication ratios (one byte): The number of multiplication ratios for each type
(e.g. the number of multiplication ratios to which the main clock can be set and the peripheral
clock can be set.)
• Multiplication ratio (one byte)
Multiplication ratio: The value of the multiplication ratio (e.g. when the clock-frequency
multiplier is four, the value of multiplication ratio will be H'04.)
Division ratio: The inverse of the division ratio, i.e. a negative number (e.g. when the clock is
divided by two, the value of division ratio will be H'FE. H'FE = D'-2)
The number of multiplication ratios returned is the same as the number of multiplication ratios
and as many groups of data are returned as there are types of multiplication.
• SUM (one byte): Checksum
Rev. 2.00 Sep. 10, 2008 Page 882 of 1132
REJ09B0364-0200