Renesas R8C/18 Series Hardware Manual page 173

R8C/18 Group, R8C/19 Group
Table 15.5 Registers Used and Settings for UART Mode
Register
UiTB 0 to 8
UiRB 0 to 8
OER,FER,PER,SUM
UiBRG 0 to 7
UiMR SMD2 to SMD0
CKDIR
STPS
PRY, PRYE
UiC0 CLK0, CLK1
TXEPT
NCH
CKPOL
UFORM
UiC1 TE
TI
RE
RI
UCON U0IRS, U1IRS
U0RRM
CNTRSEL
NOTES:
1. The bits used for transmit/receive data are as follows: Bits 0 to 6 when transfer data is 7 bits long;
bits 0 to 7 when transfer data is 8 bits long; bits 0 to 8 when transfer data is 9 bits long.
2. An external clock can be selected in UART0 only.
Table 15.6 lists the I/O Pin Functions in Clock Asynchronous Serial I/O Mode. The TXDi pin outputs "H"
level between the operating mode selection of UARTi (i = 0 or 1) and transfer start. (If the NCH bit is set
to 1 (N-channel open-drain output), this pin is in a high-impedance state.)
Table 15.6 I/O Pin Functions in Clock Asynchronous Serial I/O Mode
Pin Name
TXD0 (P1_4) Output serial data
RXD0 (P1_5) Input serial data
CLK0 (P1_6) Programmable I/O port CKDIR bit in U0MR register = 0
Input transfer clock
TXD1 (P3_7) Output serial data
RXD1 (P4_5) Input serial data
Rev.1.30 Apr 14, 2006
REJ09B0222-0130
Bit
Set transmit data
Receive data can be read
Error flag
Set a bit rate.
Set to 100b when transfer data is 7 bits long.
Set to 101b when transfer data is 8 bits long.
Set to 110b when transfer data is 9 bits long.
Select the internal clock or external clock.
Select the stop bit.
Select whether parity is included and whether odd or even.
Select the count source for the UiBRG register.
Transmit register empty flag
Select TXDi pin output mode.
Set to 0.
LSB first or MSB first can be selected when transfer data is 8 bits
long. Set to 0 when transfer data is 7 or 9 bits long.
Set to 1 to enable transmit.
Transmit buffer empty flag
Set to 1 to enable receive.
Receive complete flag
Select the source of UART0 transmit interrupt.
Set to 0.
Set to 1 to select P1_5/RXD0/CNTR01/INT11.
Function
(Cannot be used as a port when performing reception only.)
PD1_5 bit in PD1 register = 0
(P1_5 can be used as an input port when performing
transmission only.)
CKDIR bit in U0MR register = 1
PD1_6 bit in PD1 register = 0
Bits U1SEL1 to U1SEL0 in UCON register = 11b (P3_7 can be
used as a port when bits U1SEL1 to U1SEL0 = 01b and
performing reception only.)
PD4_5 bit in PD4 register = 0
Bits U1SEL1 to U1SEL0 in UCON register = 01b or 11b
(Cannot be used as a port when performing transmission only.)
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Function
(1)
.
(1)
.
Selection Method
15. Serial Interface
(2)