ST & T UPSD3212C - Manual (Page 61)

61/163
uPSD3212A, uPSD3212C, uPSD3212CV
Figure 29. Serial Port Mode 1, Block Diagram
Figure 30. Serial Port Mode 1, Waveforms
AI06826
Zero Detector
Internal Bus
Tx Control
Rx Control
Internal Bus
SBUF
Write
to
SBUF
Read
SBUF
Load
SBUF
SBUF
Input Shift Register
Shift
Serial
Port
Interrupt
Rx Clock
Start
Tx Clock
Start Shift
Shift
Send
Load SBUF
TI
RI
CL
D S
Q
1FFh
TxD
Data
Rx Detector
RxD
1-to-0
Transition
Detector
÷16
Sample
ч16
ч2
TB8
Timer1
Overflow
Timer2
Overflow
0
0 1
1
0 1
TCLK
RCLK
SMOD
AI06843
Write to SBUF
Data
Shift
TxD
T1
Rx Clock
RxD
Bit Detector
Sample Times
Shift
RI
S1P1
÷16 Reset
Receive
Transmit
D0 D1 D2 D3 D4 D5 D6 D7
Send
Tx Clock
Start Bit
Stop Bit
D0 D1 D2 D3 D4 D5 D6 D7
Start Bit
Stop Bit