SH7280 Datasheet, PDF (1493/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

Section 26 Flash Memory
The received data are checked in the following ways.
1. Input frequency
The value of the received input frequency is checked to see if it is within the range of the
minimum and maximum values of input frequency for the selected clock mode of the selected
device. A value outside the range generates an input frequency error.
2. Multiplier
The value of the received multiplier is checked to see if it matches a multiplier or divisor that
is available for the selected clock mode of the selected device. A value that does not match an
available ratio generates a frequency multiplier error.
3. Operating frequency
The operating frequency is calculated from the received input frequency and the frequency
multiplier or divisor. The input frequency is the frequency of the clock signal supplied to the
LSI, while the operating frequency is the frequency at which the LSI is actually driven. The
following formulae are used for this calculation.
Operating frequency = input frequency × multiplier, or
Operating frequency = input frequency / divisor
The calculated operating frequency is checked to see if it is within the range of the minimum
and maximum values of the operating frequency for the selected clock mode of the selected
device. A value outside the range generates an operating frequency error.
Rev. 1.00 Jun. 26, 2008 Page 1463 of 1692
REJ09B0393-0100