R8C/18 Group, R8C/19 Group
15. Serial Interface
Rev.1.30
Apr 14, 2006
Page 148 of 233
REJ09B0222-0130
Figure 15.3
Registers U0TB to U1TB, U0RB to U1RB, and U0BRG to U1BRG
UARTi Transmit Buffer Register (i = 0 or 1)
(1, 2)
Symbol
Address
After Reset
U0TB
00A3h-00A2h
Undefined
U1TB
00ABh-00AAh
Undefined
RW
NOTES:
1.
2.
Function
Transmit data
Nothing is assigned. If necessary, set to 0.
When read, the content is undefined.
—
(b15-b9)
—
(b8-b0)
When the transfer data length is 9 bits, w rite data to high byte first, then low byte.
Use the MOV instruction to w rite to this register.
WO
—
Bit Symbol
b0
b7
(b8)
b0
(b15)
b7
UARTi Receive Buffer Register (i = 0 or 1)
(1)
Symbol
Address
After Reset
U0RB
00A7h-00A6h
Undefined
U1RB
00AFh-00AEh
Undefined
RW
NOTES:
1.
2.
Nothing is assigned. If necessary, set to 0.
When read, the content is undefined.
—
(b11-b9)
—
—
(b7-b0)
—
—
(b8)
—
Function
Receive data (D7 to D0)
RO
Receive data (D8)
RO
b0
b7
(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 units.
Bits SUM, PER, FER, and OER are set to 0 (no error) w hen bits SMD2 to SMD0 in the UiMR register are set to 000b
(serial interface disabled) or the RE bit in the UiC1 register is set to 0 (receive disabled). The SUM bit is set to 0 (no
error) w hen bits PER, FER, and OER are set to 0 (no error). Bits PER and FER are set to 0 even w hen the higher byte
of the UiRB register is read out.
Also, bits PER and FER are set to 0 w hen reading the high-order byte of the UiRB register.
RO
SUM
Error sum flag
(2)
0 : No error
1 : Error
UARTi Bit Rate Register (i = 0 or 1)
(1, 2, 3)
Symbol
Address
After Reset
U0BRG
00A1h
Undefined
U1BRG
00A9h
Undefined
Setting Range
RW
NOTES:
1.
2.
3. After setting the CLK0 to CLK1 bits of the UiC0 register, w rite to the UiBRG register.
Use the MOV instruction to w rite to this register.
WO
Write to this register w hile the serial I/O is neither transmitting nor receiving.
00h to FFh
Function
Assuming the set value is n, UiBRG divides the count source by n+1
b0
b7