r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 868

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 15 Serial Communication Interface (SCI, IrDA)
• Receive shift register_3 (RSR_3)
• Transmit shift register_3 (TSR_3)
• Receive data register_3 (RDR_3)
• Transmit data register_3 (TDR_3)
• Serial mode register_3 (SMR_3)
• Serial control register_3 (SCR_3)
• Serial status register_3 (SSR_3)
• Smart card mode register_3 (SCMR_3)
• Bit rate register_3 (BRR_3)
• Receive shift register_4 (RSR_4)
• Transmit shift register_4 (TSR_4)
• Receive data register_4 (RDR_4)
• Transmit data register_4 (TDR_4)
• Serial mode register_4 (SMR_4)
• Serial control register_4 (SCR_4)
• Serial status register_4 (SSR_4)
• Smart card mode register_4 (SCMR_4)
• Bit rate register_4 (BRR_4)
15.3.1
RSR is a shift register used to receive serial data that is input to the RxD pin and convert it into
parallel data. When one byte of data has been received, it is transferred to RDR automatically.
RSR cannot be directly accessed by the CPU.
15.3.2
RDR is an 8-bit register that stores receive data. When the SCI has received one byte of serial
data, it transfers the received serial data from RSR to RDR where it is stored. After this, RSR is
receive-enabled. Since RSR and RDR function as a double buffer in this way, enables continuous
receive operations to be performed. After confirming that the RDRF bit in SSR is set to 1, read
RDR for only once. RDR cannot be written to by the CPU.
Rev. 1.00 Sep. 19, 2008 Page 840 of 1270
REJ09B0466-0100
Receive Shift Register (RSR)
Receive Data Register (RDR)