h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 414

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 13 Serial Communication Interface (SCI)
13.4.3
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 13.4.
Rev. 2.00 Dec. 05, 2005 Page 376 of 724
REJ09B0200-0200
SCK
TxD
Figure 13.4 Relationship between Output Clock and Transfer Data Phase
Clock
0
D0
D1
D2
(Asynchronous Mode)
D3
D4
1 frame
D5
D6
D7
0/1
1
1