HD6475348R Datasheet, PDF (284/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

14.3 Operation
14.3.1 Overview
Each serial communication interface channel supports serial data transfer in both asynchronous
and synchronous modes.
The communication format depends on settings in the SMR as indicated in table 14-5. The clock
source and usage of the SCK pin depend on settings in the SMR and SCR as indicated in table 14-6.
Table 14-5 Communication Formats Used by SCI
SMR
C/A CHR PE STOP Mode
Format
Parity
0
0
0
0
Asynchronous 8-Bit data None
1
1
0
Yes
1
1
0
0
7-Bit data None
1
1
0
Yes
1
1
—
——
Synchronous 8-Bit data —
Stop Bit
Length
1
2
1
2
1
2
1
2
—
Table 14-6 SCI Clock Source Selection
SMR
SCR
Clock
C/A CKE1 CKE0 Source
0
0
0
Internal
(Async
1
mode) 1
0
External
1
1
0
0
Internal
(Sync
1
mode) 1
0
External
1
* Cannot be used by the SCI.
SCK Pin
I/O port*
Clock output at same frequency as baud rate
Clock input at 16 times the baud rate frequency
Serial clock output
Serial clock input
Transmitting and receiving operations in the two modes are described next.
270