
R8C/36T-A Group
20. Serial Interface (UART2)
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0240EJ0010 Rev.0.10
Page 404 of 728
Aug 05, 2011
20.2.4
UART2 Transmit/Receive Control Register 0 (U2C0)
Notes:
1. If bits CLK0 and CLK1 are changed, set the U2BRG register again.
3. Can only be selected in SIO/UART mode. In other modes, because the CRD bit is set to 1 (CTS/RTS function
disabled), the value set to this bit is invalid.
4. Can only be set in SIO/UART mode. In other modes, set to 1 (CTS/RTS function disabled).
5. Set to 1 (pins TXD2/SDA2 and SCL2 are set to N-channel open-drain output) while in I2C mode.
6. When UART2 is not used, set the NCH bit to 0 (pins TXD2/SDA2 and SCL2 are set to CMOS output).
7. Can only be set in SIO mode. In other modes, set to 0 (transmit data is output at the falling edge and receive data
is input at the rising edge of the transfer clock).
8. Can only be selected while data transfer length is 8 bits in SIO/UART mode. In I2C mode, set to 1 (MSB first). In
modes other than I2C and SIO/UART mode, set to 0 (LSB first).
Address 000C4h
Bit
b7b6
b5b4b3
b2b1b0
After Reset
0
000
1000
Bit
Symbol
Bit Name
Function
R/W
b0
CLK0
U2BRG count source select bits
(1)b1 b0
00: f1
01: f8
10: f32
R/W
b1
CLK1
R/W
b2
CRS
CTS/RTS function select bit
(3)Enabled when CRD = 0
0: CTS function selected
1: RTS function selected
R/W
b3
TXEPT
Transmit register empty flag
0: Data present in the transmit register
(transmission in progress)
1: No data in the transmit register
(transmission completed)
R
b4
CRD
0: CTS/RTS function enabled
1: CTS/RTS function disabled
R/W
b5
NCH
0: Pins TXD2/SDA2 and SCL2 are set to CMOS
output
1: Pins TXD2/SDA2 and SCL2 are set to N-
channel open-drain output
R/W
b6
CKPOL
CLK polarity select bit
(7)0: Transmit data is output at the falling edge and
receive data is input at the rising edge of the
transfer clock
1: Transmit data is output at the rising edge and
receive data is input at the falling edge of the
transfer clock
R/W
b7
UFORM Transfer format select bit
(8)0: LSB first
1: MSB first
R/W