UPSD3354DV-40U6 Datasheet, PDF (117/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

UPSD33xx
Serial UART interfaces
Figure 31. UART mode 2, block diagram
fOSC/32
Internal bus
TB8
Write
to
SBUF
÷2
D SQ
SBUF
TxD
pin
CL
01
SMOD
Zero detector
Start
Shift Data
Tx Control
÷16
Tx Clock
TI
Send
Serial
port
interrupt
) _Sample
t(s ^1-to-0
transition
c _detector
÷16
Rx Clock
Start
RI
Load SBUF
Rx Control
1FFh
Shift
du _{Rx detector}
ro _{Input shift register}
te ^{P RxD}
pin
Load
SBUF
Shift
sole _Read
b_SBUF
SBUF
- ^O Internal bus
ct(s) _{Figure 32. UART mode 2, timing diagram}
du _{Tx Clock}
ro ^{Write to SBUF}
P Send
te ^Data
Shift
le_TxD
o _TI
s _{Stop Bit}
Ob ^Generator
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7 TB8 Stop Bit
AI06844
Transmit
Rx Clock
RxD
Bit Detector
Sample Times
Shift
RI
Start Bit
D0
D1
D2
D3
D4
D5
D6
D7 RB8 Stop Bit
Receive
AI06845
Doc ID 9685 Rev 7
117/272