Uart/Sio Serial Input Data Register (Rdr0) - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 20 UART/SIO
20.5.4

UART/SIO Serial Input Data Register (RDR0)

The UART/SIO serial input data register (RDR0) is used to input (receive) serial data.
UART/SIO Serial Input Data Register (RDR0)
Figure 20.5-5 shows the bit configuration of the UART/SIO serial input data register.
Address
005A RDR0
H
R/WX: Read only (Readable, writing has no effect on operation)
This register stores received data. The serial data signals sent to the serial data input pin (UI0 pin) is
converted by the shift register and stored in this register.
When received data is set correctly in this register, the receive data register full (RDRF) bit is set to "1". At
this time, an interrupt occurs if reception interrupt requests have been enabled. If an RDRF bit check by the
program or using an interruption shows that received data is stored in this register, the reading of the
content for this register clears the RDRF flag to "0".
When the character bit length (CBL1, 0) is set to shorter than 8 bits, the excess upper bits (beyond the set
bit length) are set to "0".
340
Figure 20.5-5 UART/SIO Serial Input Data Register (RDR0)
bit7 bit6 bit5
RD7 RD6 RD5
R/WX R/WX R/WX
bit4 bit3 bit2
RD4 RD3 RD2
R/WX R/WX R/WX R/WX
bit1 bit0 Initial value
RD1 RD0 00000000
R/WX
B