HD6417750RF240V Datasheet, PDF (377/606 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 14 Serial Communication Interface (SCI)
14.4.3 Clock
Either an internal clock generated by the on-chip 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/A bit in
SMR and the CKE0 and CKE1 bits in SCR. When an external clock is input at the SCK pin, the
clock frequency should be 16 times the bit rate used.
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 in the middle of the transmit data, as shown in figure 14.4.
SCK
TxD
0 D0 D1 D2 D3 D4 D5 D6 D7 0/1 1 1
1 frame
Figure 14.4 Relationship between Output Clock and Transfer Data Phase
(Asynchronous Mode)
Rev. 7.00 Sep. 11, 2009 Page 341 of 566
REJ09B0211-0700