Datasheet
Section 15 Serial Communication Interface (SCI)
Rev. 6.00 Mar. 18, 2010 Page 553 of 982
REJ09B0054-0600
15.3.4 Transmit Shift Register (TSR)
TSR is a shift register that transmits serial data. To perform serial data transmission, the SCI first
transfers transmit data from TDR to TSR, then sends the data to the TxD pin. TSR cannot be
directly accessed by the CPU.
15.3.5 Serial Mode Register (SMR)
SMR is used to set the SCI’s serial transfer format and select the baud rate generator clock source.
Some bit functions of SMR differ between normal serial communication interface mode and Smart
Card interface mode.
• Normal Serial Communication Interface Mode (When SMIF in SCMR is 0)
Bit
Bit Name
Initial
Value
R/W
Description
7 C/A 0 R/W Communication Mode
0: Asynchronous mode
1: Clocked synchronous mode
6 CHR 0 R/W Character Length (enabled only in asynchronous
mode)
0: Selects 8 bits as the data length.
1: Selects 7 bits as the data length. LSB-first is
fixed and the MSB (bit 7) of TDR is not
transmitted in transmission.
In clocked synchronous mode, a fixed data length
of 8 bits is used.
5 PE 0 R/W Parity Enable (enabled only in asynchronous
mode)
When this bit is set to 1, the parity bit is added to
transmit data before transmission, and the parity
bit is checked in reception. For a multiprocessor
format, parity bit addition and checking are not
performed regardless of the PE bit setting.