
R8C/14 Group, R8C/15 Group 14. Serial Interface
Rev.2.10 Jan 19, 2006 Page 127 of 253
REJ09B0164-0210
Figure 14.3 U0TB, U0RB and U0BRG Registers
UART0 Receive Buffer Register
(1)
Symbol Address After Reset
U0RB
00A7h-00A6h Indeterminate
RW
NOTES :
1.
2.
Nothing is assigned. When w rite, set to “0”.
When read, its content is indeterminate.
—
(b11-b9)
—
—
(b7-b0)
—
—
(b8)
—
Function
Receive data (D7 to D0)
RO
Receive data (D8)
RO
b0b7
(b15)
b7
(b8)
b0
Bit Symbol Bit Name
OER
Overrun Error Flag
(2)
0 : No overrun error
1 : Overrun error
RO
RO
FER
Framing Error Flag
(2)
0 : No framing error
1 : Framing error
RO
PER
Parity Error Flag
(2)
0 : No parity error
1 : Parity error
Read out the UiRB register in 16-bit unit.
The SUM, PER, FER and OER bits are set to “0” (no error) when the SMD2 to SMD0 bits in the UiMR register are set to
“000b” (serial interface disabled) or the RE bit in the U0C1 register is set to “0” (receive disable). The SUM bit is set to
“0” (no error) w hen the PER, FER and OER bits are set to “0” (no error).
The PER and FER bits are set to “0” even when the higher byte of the U0RB register is read out.
ROSUM
Error Sum Flag
(2)
0 : No error
1 : Error
UART0 Transmit Buffer Register
(1, 2)
Symbol Address After Reset
U0TB
00A3h-00A2h Indeterminate
RW
NOTES :
1.
2.
(b15)
b7
(b8)
b0
b0b7
When the transfer data length is 9-bit long, w rite to high-byte data first then low-byte data.
Use the MOV instruction to write to this register.
Function
WO
—
—
(b8-b0)
—
(b15-b9)
Transmit data
Nothing is assigned. When w rite, set to “0”.
When read, its content is indeterminate.
UART0 Bit Rate Register
(1, 2, 3)
Symbol Address After Reset
U0BRG
00A1h Indeterminate
Setting Range RW
NOTES :
1.
2.
3.
b0
Use the MOV instruction to write to this register.
WO
Write to this register w hile the serial I/O is neither transmitting nor receiving.
00h to FFh
Function
Assuming that set value is n, U0BRG divides the count source by
n+1
After setting the CLK0 to CLK1 bits of the U0C0 register, write to the U0BRG register.
b7
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