Renesas H8S/2158 User Manual page 451

Bit Bit Name
1 CKE1
0 CKE0
Legend:
X: Don't care
Section 16 Serial Communication Interface (SCI, IrDA, and CRC)
Initial Value R/W
0 R/W
0 R/W
Description
Clock Enable 1,0
These bits select the clock source and SCK pin
function.
Asynchronous mode
00: Internal clock
(SCK pin functions as I/O port.)
01: Internal clock
(Outputs a clock of the same frequency as the
bit rate from the SCK pin.)
1X: External clock
(Inputs a clock with a frequency 16 times the bit
rate from the SCK pin.)
Clocked synchronous mode
0X: Internal clock (SCK pin functions as clock
output.)
1X: External clock (SCK pin functions as clock
input.)
Rev. 3.00 Jan 25, 2006 page 397 of 872
REJ09B0286-0300