
R8C/14 Group, R8C/15 Group 14. Serial Interface
Rev.2.10 Jan 19, 2006 Page 128 of 253
REJ09B0164-0210
Figure 14.4 U0MR and U0C0 Registers
UART0 Transmit / Receive Mode Register
Symbol Address After Reset
U0MR 00A0h 00h
Bit Symbol Bit Name Function RW
NOTES :
1.
Internal / External Clock Select
Bit
0 : Internal clock
1 : External clock
(1)
Stop Bit Length Select Bit
—
(b7)
Reserved Bit
RW
Odd / Even Parity Select Bit Enables when PRYE = 1
0 : Odd parity
1 : Even parity
PRYE
Parity Enable Bit 0 : Parity disabled
1 : Parity enabled
RW
Set to “0”
Set the PD1_6 bit in the PD1 register to “0” (input).
SMD2 RW
RW
STPS RW
0 : 1 Stop Bit
1 : 2 Stop Bits
CKDIR
PRY RW
RW
Serial Interface Mode Select Bit
b2 b1 b0
0 0 0 : Serial interface disabled
0 0 1 : Clock synchronous serial I/O mode
1 0 0 : UART mode transfer data 7 bits long
1 0 1 : UART mode transfer data 8 bits long
1 1 0 : UART mode transfer data 9 bits long
Other than above : Do not set
SMD1
b7 b6 b5 b4
0
b3 b2 b1 b0
SMD0 RW
UART0 Transmit / Receive Control Register 0
Symbol Address After Reset
U0C0
00A4h 08h
Bit Symbol Bit Name Function RW
NOTES :
1.
RW
Nothing is assigned. When write, set to “0”.
When read, its content is “0”.
Data Output Select Bit 0 : TXD0 pin is a pin of CMOS output
1 : TXD0 pin is a pin of N-channel open drain output
UFORM
Transfer Format Select Bit 0 : LSB first
1 : MSB first
RW
Reserved Bit
CLK Polarity Select Bit 0 : Transmit data is output at falling edge of transfer
clock and receive data is input at rising edge
1 : Transmit data is output at rising edge of transfer
clock and receive data is input at falling edge
Set to “0”
Transmit Register Empty
Flag
0 : Data in transmit register (during transmit)
1 : No data in transmit register (transmit completed)
CLK1 RW
BRG Count Source Select
Bit
(1)
b1 b0
0 0 : Selects f1
0 1 : Selects f8
1 0 : Selects f32
1 1 : Do not set
NCH
RW
RW
CKPOL
—
(b2)
RW
RO
—
(b4)
—
b7 b6 b5 b4
If the BRG count source is sw itched, set the U0BRG register again.
b3 b2
TXEPT
b1 b0
0
CLK0
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