R8C/38T-A Group
20. Serial Interface (UART2)
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 410 of 730
Aug 05, 2011
20.2.6
UART2 Receive Buffer Register (U2RB)
Notes:
1. Bit function differs depending on whether the multiprocessor communication function is being used.
2. Enabled only in I2C mode. Disabled in other modes. Writing 0 clears this bit. Writing 1 has no effect.
3. When bits SMD2 to SMD0 in the U2MR register are set to 000b (serial interface disabled) or the RE bit in the
U2C1 register is set to 0 (reception disabled), all of bits SUM, PER, FER, and OER are set to 0 (no error). The
SUM bit is set to 0 (no error) when all of bits PER, FER, and OER are set to 0 (no error). Bits PER and FER are
set to 0 when the U2RB register is read.
When setting bits SMD2 to SMD0 in the U2MR register to 000b, set the TE bit in the U2C1 register to 0
(transmission disabled) and the RE bit to 0 (reception disabled).
4. Enabled in all modes.
5. Enabled only in UART and multiprocessor modes. Disabled in other modes.
Use the MOV instruction to write the receive data (D0 to D8).
Access the U2RB register in word (16-bit) units.
Address 000C6h
Bit
b7b6
b5b4b3
b2b1b0
Symbol
After Reset
0
000
0000
Bit
b15
b14
b13
b12
b11
b10
b9
b8
Symbol
After Reset
0
000
0000
Bit
Symbol
Bit Name
Function
R/W
b0
—
Receive data (D0 to D7)
R
b1
—
R
b2
—
R
b3
—
R
b4
—
R
b5
—
R
b6
—
R
b7
—
R
b8
MPRB
Receive data (D8)/multiprocessor bit
[When the multiprocessor communication function
is not used]
Receive data (D8)
[When the multiprocessor communication function
is used]
When the MPRB bit is set to 0, received D0 to D7
are data fields.
When the MPRB bit is set to 1, received D0 to D7
are ID fields.
R
b9
—
Nothing is assigned. The write value must be 0. The read value is undefined.
—
b10
—
b11
ABT
Arbitration lost detection flag
(2)0: Not detected
1: Detected
b12
OER
0: No overrun error
1: Overrun error
R
b13
FER
0: No framing error
1: Framing error
R
b14
PER
0: No parity error
1: Parity error
R
b15
SUM
0: No error
1: Error
R