222
Pin Configuration: Table 10.4 shows the SCI3 pin configuration.
Table 10.4
Pin Configuration
Name
Abbrev.
I/O
Function
SCI3 clock
SCK
3
I/O
SCI3 clock input/output
SCI3 receive data input
RXD
Input
SCI3 receive data input
SCI3 transmit data output
TXD
Output
SCI3 transmit data output
Register Configuration: Table 10.5 shows the SCI3 internal register configuration.
Table 10.5
SCI3 Registers
Name
Abbrev.
R/W
Initial Value
Address
Serial mode register
SMR
R/W
H'00
H'FFA8
Bit rate register
BRR
R/W
H'FF
H'FFA9
Serial control register 3
SCR3
R/W
H'00
H'FFAA
Transmit data register
TDR
R/W
H'FF
H'FFAB
Serial status register
SSR
R/W
H'84
H'FFAC
Receive data register
RDR
R
H'00
H'FFAD
Transmit shift register
TSR
Not possible
—
—
Receive shift register
RSR
Not possible
—
—
Bit rate counter
BRC
Not possible
—
—
10.3.2
Register Descriptions
Receive Shift Register (RSR)
7
—
6
—
5
—
4
—
3
—
0
—
2
—
1
—
Bit
Read/Write
The receive shift register (RSR) is for receiving serial data.
Serial data is input in LSB-first order into RSR from pin RXD, converting it to parallel data. After
each byte of data has been received, the byte is automatically transferred to the receive data
register (RDR).
RSR cannot be read or written directly by the CPU.