R8C/1A Group, R8C/1B Group
15. Serial Interface
Rev.1.30
Dec 08, 2006
Page 157 of 315
REJ09B0252-0130
Figure 15.6
Registers U0C1 to U1C1, and UCON
UARTi Transmit / Receive Control Register 1 (i = 0 or 1)
Symbol
Address
After Reset
U0C1
00A5h
02h
U1C1
00ADh
02h
Bit Symbol
Bit Name
Function
RW
NOTE :
1.
b3 b2 b1 b0
Nothing is assigned. If necessary, set to 0.
When read, the content is 0.
Transmit enable bit
0 : Disables transmission.
1 : Enables transmission.
Transmit buffer empty flag
0 : Disables reception.
1 : Enables reception.
b7 b6 b5 b4
The RI bit is set to 0 w hen the higher byte of the UiRB register is read out.
RW
TI
RO
0 : Data in UiTB register
1 : No data in UiTB register
TE
RE
—
(b7-b4)
—
Receive enable bit
RO
RW
RI
Receive complete flag
(1)
0 : No data in UiRB register
1 : Data in UiRB register
UART Transmit / Receive Control Register 2
Symbol
Address
After Reset
UCON
00B0h
00h
Bit Symbol
Bit Name
Function
RW
0 : P1_5/RXD0
P1_7/CNTR00/INT10
______
1 : P1_5/RXD0/CNTR01/INT11
______
P1_7
NOTE :
1.
U1SEL0
RW
UART1 pin (P3_7/TXD1,
P4_5/RXD1) select bits
b5 b4
0 0 : P3_7, P4_5
0 1 : P3_7, RXD1
1 0 : Do not set.
1 1 : TXD1, RXD1
b3 b2
—
(b3)
b1 b0
0
U0RRM
RW
U1IRS
RW
UART0 continuous receive
mode enable bit
0 : Disables continuous receive mode.
1 : Enables continuous receive mode.
UART1 transmit interrupt
source select bit
0 : Transmit buffer empty (TI = 1)
1 : Transmit completed (TXEPT = 1)
0
RW
U0IRS
UART0 transmit interrupt
source select bit
0 : Transmit buffer empty (TI = 1)
1 : Transmit completed (TXEPT = 1)
b7 b6 b5 b4
The CNTRSEL bit selects the input pin of the CNTR0 (INTI
_____
) signal.
When the CNTR0 signal is output, it is output from the CNTR00 pin regardless of the CNTRSEL bit setting.
Reserved bit
Set to 0.
CNTR0 signal pin select bit
(1)
RW
RW
CNTRSEL
U1SEL1
RW
—
(b6)
Reserved bit
Set to 0.
RW