HD6412373R RENESAS [Renesas Technology Corp], HD6412373R Datasheet - Page 1006

• Manufacturer Part Number: HD6412373R
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 21 Flash Memory (0.18-μm F-ZTAT Version)
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:
When the new bit rate is selectable, the rate will be set in the register after sending ACK in
response. The host will send an ACK with the new bit rate for confirmation and the boot program
will response with that rate.
Confirmation
• Confirmation, H'06, (one byte): Confirmation of a new bit rate
Response
• Response, H'06, (one byte): Response to confirmation of a new bit rate
The sequence of new bit-rate selection is shown in figure 21.20.
Rev.7.00 Mar. 18, 2009 page 938 of 1136
REJ09B0109-0700
Waiting for one-bit period
Setting a new bit rate
at the specified bit rate
Error (%) = {[
H'06
Host
H'06
(N + 1) × B × 64 × 2
Figure 21.20 New Bit-Rate Selection Sequence
φ × 10
H'06 (ACK) with the new bit rate
H'06 (ACK) with the new bit rate
6
Setting a new bit rate
(2×n − 1)
H'06 (ACK)
] − 1} × 100
Setting a new bit rate
Boot program