Register Descriptions; Receive Shift Register (Rsr); Receive Data Register (Rdr) - Renesas RX100 Series User Manual

RX13T Group
23.2

Register Descriptions

23.2.1

Receive Shift Register (RSR)

RSR is a shift register which is used to receive serial data input from the RXDn pin and converts it into parallel data.
When one frame of data has been received, it is automatically transferred to the RDR register.
The RSR register cannot be directly accessed by the CPU.
23.2.2

Receive Data Register (RDR)

Address(es): SCI1.RDR 0008 A025h, SCI5.RDR 0008 A0A5h, SCI12.RDR 0008 B305h
b7 b6
Value after reset: 0 0
RDR is an 8-bit register that stores receive data.
When one frame of serial data has been received, the received serial data is transferred from RSR to RDR. Then the RSR
register can receive the next data.
Since RSR and RDR function as a double buffer in this way, continuous receive operations can be performed.
Read RDR only once after a receive data full interrupt (RXI) has occurred. Note that if next one frame of data is received
before reading receive data from RDR, an overrun error occurs.
RDR cannot be written to by the CPU.
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
b5 b4 b3 b2
0 0 0 0
23. Serial Communications Interface (SCIg, SCIh)
b1 b0
0 0
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