Renesas H8S Series Hardware Manual page 804

Section 21 Flash Memory (0.18-µm F-ZTAT Version)
(2) Programming/Erasing Initialization
The on-chip programming/erasing program to be downloaded includes the initialization program.
A pulse of the specified width must be applied when programming or erasing. The specified pulse
width is made by the method in which a wait loop is configured by CPU instructions. The
operating frequency of the CPU must be set too.
The initialization program is used to set the above values as parameters of the
programming/erasing program that was downloaded.
(a) Flash programming/erasing frequency control parameter (FPEFEQ: general register
ER0 of CPU)
This parameter sets the operating frequency of the CPU. The settable range of the operating
frequency in this LSI is 4 to 20 MHz.
Initial
Bit Bit Name Value
31 to 16  
15 to 0 F15 to F0 
Rev. 3.00 Jul. 14, 2005 Page 756 of 986
REJ09B0098-0300
R/W Description

Unused
These bits should be cleared to 0.
R/W Frequency Set
These bits set the operating frequency of the CPU. The
setting value must be calculated with the following
procedure.
1. The operating frequency shown in MHz units must be
rounded off to two decimals.
2. The value multiplied by 100 is converted to the
hexadecimal numeral and written to the FPEFEQ
parameter (general register ER0).
For example, when the operating frequency of the CPU
is 20.000 MHz, the setting value is as follows:
1. 20.000 is rounded off to two decimals, thus becoming
20.00.
2. The formula of 20.00 × 100 = 2000 is converted to
the hexadecimal numeral and H'07D0 is set to ER0.