HD64F3039F18 Datasheet, PDF (360/710 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8 Family / H8/300H Series

Section 11 Serial Communication Interface
11.2 Register Descriptions
11.2.1 Receive Shift Register (RSR)
RSR is an 8-bit register that receives serial data.
Bit
7
6
5
4
3
2
1
0
Read/Write
—
—
—
—
—
—
—
—
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 1 byte has been received, it is automatically
transferred to RDR. The CPU cannot read or write RSR directly.
11.2.2 Receive Data Register (RDR)
RDR is an 8-bit register that stores received serial data.
Bit
7
6
5
4
3
2
1
0
Initial value
0
0
0
0
0
0
0
0
Read/Write
R
R
R
R
R
R
R
R
When the SCI finishes receiving 1 byte of serial data, it transfers the received data from RSR into
RDR for storage. 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.3.00 Mar. 26, 2007 Page 336 of 682
REJ09B0353-0300