Hitachi H8S/2199 Hardware Manual page 435

Single-chip microcomputer

Table of Contents

Either an internal clock generated by the built-in baud rate generator or an external clock input

at the SCK pin can be selected as the SCI's serial clock, according to the setting of the C/$ bit

in SMR1 and the CKE1 and CKE0 bits in SCR1. For details of SCI clock source selection, see

When an external clock is input at the SCK pin, the clock frequency should be 16 times the bit

When the SCI is operated on an internal clock, the clock can be output from the SCK pin. The

frequency of the clock output in this case is equal to the bit rate, and the phase is such that the

rising edge of the clock is at the center of each transmit data bit, as shown in figure 22.3.

Figure 22.3 Relation between Output Clock and Transfer Data Phase

Rev. 1.0, 02/00, page 426 of 1141

(Asynchronous Mode)