SH7706 Datasheet, PDF (442/749 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7700 Series

Section 14 Serial Communication Interface (SCI)
Clock: An internal clock generated by the on-chip baud rate generator or an external clock input
from the SCK0 pin can be selected as the SCI transmit/receive clock. The clock source is selected
by the C/A bit in SCSMR and bits CKE1 and CKE0 in the SCSCR (table 14.9).
When an external clock is input on the SCK0 pin, it must have a frequency equal to 16 times the
desired bit rate.
When the SCI operates on an internal clock, it can output a clock signal on the SCK0 pin. The
frequency of this output clock is equal to the bit rate. The phase is aligned as in figure 14.6 so that
the rising edge of the clock occurs at the center of each transmit data bit.
0 D0 D1 D2 D3 D4 D5 D6 D7 0/1 1
1
1 frame
Figure 14.6 Output Clock and Serial Data Timing (Asynchronous Mode)
Rev. 5.00 May 29, 2006 page 394 of 698
REJ09B0146-0500