HD6413008F RENESAS [Renesas Technology Corp], HD6413008F Datasheet - Page 370

• Manufacturer Part Number: HD6413008F
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
• Manufacturer: RENESAS [Renesas Technology Corp]

12. Serial Communication Interface
12.2
12.2.1
RSR is the register that receives serial data.
The SCI loads serial data input at the RxD pin into RSR in the order received, LSB (bit 0) first,
thereby converting the data to parallel data. When one byte of data has been received, it is
automatically transferred to RDR. The CPU cannot read or write RSR directly.
12.2.2
RDR is the register that stores received serial data.
When the SCI has received one byte of serial data, it transfers the received data from RSR into
RDR for storage, completing the receive operation. RSR is then ready to receive the next data.
This double-buffering allows data to be received continuously.
RDR is a read-only register. Its contents cannot be modified by the CPU. RDR is initialized to
H'00 by a reset and in standby mode.
Rev.4.00 Aug. 20, 2007 Page 326 of 638
REJ09B0395-0400
Bit
Read/Write
Bit
Initial value
Read/Write
Register Descriptions
Receive Shift Register (RSR)
Receive Data Register (RDR)
R
7
0
⎯
7
R
6
0
⎯
6
R
0
5
⎯
5
R
0
4
⎯
4
R
0
3
⎯
3
R
0
2
⎯
2
1
R
⎯
0
1
0
R
⎯
0
0