CHAPTER 13 UART
13.4.5
Serial Output Data Register (SODR)
The serial output data register (SODR) sends out (transmits) serial data.
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Serial Output Data Register (SODR)
Figure 13.4-7 shows the configuration of the serial output data register bits.
Address
bit7
002B
H
W
: Write only
: Undefined
X
When transmission is enabled, writing data to be transmitted into this register after reading the SSD register
sends the data to be transmitted to the transmission shift register, converts it into the serial format, then
outputs it from the serial data output pin (UO pin).
When the transmitted data is written into the SODR register, the transmitted data flag bit is cleared with
"0". After the transmitted data is sent to the transmission shift register, the transmitted data flag bit is set to
"1", the data transmitted next then becomes writable. At this time, if the transmission interrupt request is
enabled, an interrupt is generated. Write the data transmitted next when a transmission interrupt occurs or
while the transmitted data flag bit is "1".
298
Figure 13.4-7 Serial Output Data Register (SODR)
bit6
bit5
W
W
W
bit4
bit3
bit2
W
W
W
bit1
bit0
Initial value
XXXXXXXX
W
W
B