Renesas H8S/2100 Series Hardware Manual page 810

Section 24 Flash Memory
• ERROR: (one byte): Error code
H'11:
H'24:
H'25:
H'26:
H'27:
(4) Receive Data Check
The methods for checking of receive data are listed below.
1. Input frequency
The received value of the input frequency is checked to ensure that it is within the range of
minimum to maximum frequencies which matches the clock modes of the specified device.
When the value is out of this range, an input-frequency error is generated.
2. Division ratio
The received value of the division ratio is checked to ensure that it matches the clock modes of
the specified device. When the value is out of this range, a division ratio error is generated.
3. Operating frequency error
Operating frequency is calculated from the received value of the input frequency and the
division ratio. The input frequency is input to the LSI and the LSI is operated at the operating
frequency. The expression is given below.
Operating frequency = Input frequency ÷ Division ratio
The calculated operating frequency should be checked to ensure that it is within the range of
minimum to maximum frequencies which are available with the clock modes of the specified
device. When it is out of this range, an operating frequency error is generated.
4. Bit rate
To facilitate error checking, the value (n) of clock select (CKS) in the serial mode register
(SMR), and the value (N) in the bit rate register (BRR), which are found from the peripheral
operating clock frequency (φ) and bit rate (B), are used to calculate the error rate to ensure that
it is less than 4%. If the error is more than 4%, a bit rate error is generated. The error is
calculated using the following expression:
Error (%) = {[
Rev. 1.00 May 09, 2008 Page 784 of 954
REJ09B0462-0100
Sum checking error
Bit-rate selection error
The rate is not available.
Error in input frequency
This input frequency is not within the specified range.
Division ratio error
The ratio does not match an available ratio.
Operating frequency error
The frequency is not within the specified range.
φ × 10
6
(N + 1) × B × 64 × 2 (2×n − 1)
] − 1} × 100