Renesas M32R/ECU Series, User Manual

Page: 510 / 839

12
12-19
Serial I/O
12.2 Serial I/O Related Registers
32180 Group User's Manual (Rev.1.0)
12.2.5 SIO Receive Buffer Registers
SIO0 Receive Buffer Register (S0RXB) <Address: H'0080 0114>
SIO1 Receive Buffer Register (S1RXB) <Address: H'0080 0124>
SIO2 Receive Buffer Register (S2RXB) <Address: H'0080 0134>
SIO3 Receive Buffer Register (S3RXB) <Address: H'0080 0144>
SIO4 Receive Buffer Register (S4RXB) <Address: H'0080 0A14>
SIO5 Receive Buffer Register (S5RXB) <Address: H'0080 0A24>
b0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 b15
RDATA
? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
<After reset: Undefined>
b Bit Name Function R W
0–6 No function assigned. 0 –
8–15 RDATA Received data is stored in these bits. R –
Received data
The SIO Receive Buffer Registers are used to store the received data. When the serial I/O has finished receiving
data, the content of the SIO Receive Shift Register is transferred to the SIO Receive Buffer Register. These
registers are a read-only register.
For the 7-bit data format (UART mode only), data is set in bits 9–15, with bits 8 and 7 always set to "0". For the
8-bit data format, data is set in bits 8–15, with bit 7 always set to "0".
When reading the content of the SIO Receive Buffer Register after reception is completed, if the serial I/O
finishes receiving the next data before the previous data is not read out, an overrun error occurs and the subse-
quent received data are not transferred to the Receive Buffer Register.
To restart normal receive operation, clear the Receive Control Register REN (Receive Enable) bit to "0".
Note: For the 7-bit and 8-bit data formats, the register can be accessed bytewise.