Renesas H8S Series Hardware Manual page 356

Section 14 Serial Communication Interface (SCI)
Bit Bit Name Initial Value
1 CKS1 0
0 CKS0 0
Rev. 6.00 Mar 15, 2006 page 320 of 570
REJ09B0211-0600
R/W Description
R/W Clock Select 0 and 1
R/W These bits select the clock source for the baud rate
generator.
00: φ clock (n = 0)
01: φ/4 clock (n = 1)
10: φ/16 clock (n = 2)
11: φ/64 clock (n = 3)
For the relationship between the bit rate register
setting and the baud rate, see section 14.3.9, Bit Rate
Register (BRR). n is the decimal representation of the
value of n in BRR (see section 14.3.9, Bit Rate
Register (BRR)).