uPSD3212A, uPSD3212C, uPSD3212CV
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Serial Port Control RegisterThe serial port control and status register is theSpecial Function Register SCON (SCON2 for thesecond port), shown in Figure 27. This register(see Tables 43 and 44) contains not only the modeselection bits, but also the 9th data bit for transmitand receive (TB8 and RB8), and the Serial Port In-terrupt Bits (TI and RI ) .Figure 27. Serial Port Mode 0, Block DiagramTable 43. Serial Port Control Register (SCON)

76543210

SM0 SM1 SM2 REN TB8 RB8 TI RI

AI06824
Zero Detector
Internal Bus
Tx Control
Rx Control
Internal Bus
SBUF
Write
to
SBUF
Read
SBUF
Load
SBUF
SBUF
Input Shift Register
Shift
Shift
Clock
Serial
Port
Interrupt
S6
REN
R1
Rx Clock
Start
Tx Clock
Start Shift
Shift
Send
Receive
T
R
CL
DS
Q
7 6 5 4 3 2 1 0
RxD
P3.0 Alt
Input
Function
RxD
P3.0 Alt
Output
Function
TxD
P3.1 Alt
Output
Function