hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 377

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

10.2
10.2.1
RSR is a register used to receive serial data. Serial data input to RSR from the RXD
the order in which it is received, starting from the LSB (bit 0), and converted to parallel data.
When one byte of data is received, it is transferred to RDR automatically.
RSR cannot be read or written directly by the CPU.
10.2.2
RDR is an 8-bit register that stores received serial data.
When reception of one byte of data is finished, the received data is transferred from RSR to RDR,
and the receive operation is completed. RSR is then able to receive data. RSR and RDR are
double-buffered, allowing consecutive receive operations.
RDR is a read-only register, and cannot be written by the CPU.
RDR is initialized to H'00 upon reset, and in standby, module standby or watch mode.
Bit
Read/Write
Bit
Initial value
Read/Write
Receive Shift Register (RSR)
Register Descriptions
Receive Data Register (RDR)
RDR7

R
7
7
0
RDR6

R
6
6
0
RDR5

R
5
5
0
RDR4

R
4
4
0
Section 10 Serial Communication Interface
Rev. 7.00 Mar 10, 2005 page 335 of 652
RDR3

R
3
3
0
RDR2

R
2
2
0
RDR1
REJ09B0042-0700

R
1
1
0
32
pin is set in
RDR0

R
0
0
0