
R8C/3GM Group
21. Serial Interface (UART0)
R01UH0284EJ0100 Rev.1.00
Aug 09, 2011
21.2.4
UART0 Transmit/Receive Control Register 0 (U0C0)
Note:
1. If the BRG count source is switched, set the U0BRG register again.
21.2.5
UART0 Transmit/Receive Control Register 1 (U0C1)
Notes:
1. The RI bit is set to 0 when the higher byte of the U0RB register is read.
2. In UART mode, set the U0RRM bit to 0 (continuous receive mode disabled).
Address 00A4h
Bit
b7b6b5
b4b3b2
b1b0
After Reset
000
010
00
Bit
Symbol
Bit Name
Function
R/W
b0
CLK0
BRG count source select bit
(1)b1 b0
0 0: f1 selected
0 1: f8 selected
1 0: f32 selected
1 1: fC selected
R/W
b1
CLK1
R/W
b2
—
Reserved bit
Set to 0.
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
—
Nothing is assigned. If necessary, set to 0. When read, the content is 0.
—
b5
NCH
Data output select bit
0: TXD0 pin set to CMOS output
1: TXD0 pin set to N-channel open-drain output
R/W
b6
CKPOL
CLK polarity select bit
0: Transmit data output at the falling edge and receive
data input at the rising edge of the transfer clock
1: Transmit data output at the rising edge and receive
data input at the falling edge of the transfer clock
R/W
b7
UFORM Transfer format select bit
0: LSB first
1: MSB first
R/W
Address 00A5h
Bit
b7b6b5
b4b3b2
b1b0
Symbol
After Reset
000
10
Bit
Symbol
Bit Name
Function
R/W
b0
TE
Transmit enable bit
0: Transmission disabled
1: Transmission enabled
R/W
b1
TI
Transmit buffer empty flag
0: Data present in the U0TB register
1: No data in the U0TB register
R
b2
RE
Receive enable bit
0: Reception disabled
1: Reception enabled
R/W
b3
RI
Receive complete flag
(1)0: No data in the U0RB register
1: Data present in the U0RB register
R
b4
U0IRS
UART0 transmit interrupt source
select bit
0: Transmission buffer empty (TI = 1)
1: Transmission completed (TXEPT = 1)
R/W
b5
U0RRM UART0 continuous receive mode
0: Continuous receive mode disabled
1: Continuous receive mode enabled
R/W
b6
—
Nothing is assigned. If necessary, set to 0. When read, the content is 0.
—
b7
—