st20-gp1 STMicroelectronics, st20-gp1 Datasheet - Page 72

• Manufacturer Part Number: st20-gp1
• Description: Gps Processor
• Manufacturer: STMicroelectronics

ST20-GP1
13 UART interface (ASC)
The UART interface, also referred to as the Asynchronous Serial Controller (ASC), provides serial
communication between the ST20 device and other microcontrollers, microprocessors or external
peripherals.
The ASC supports full-duplex asynchronous communication, where both the transmitter and the
receiver use the same data frame format and the same baud rate. Data is transmitted on the
transmit data output pin (TXD) and received on the receive data input pin (RXD).
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RXD
LoopBack
0
MUX
1
Sampling
clock
CPU
ParityOdd
RxEnable
Figure 13.1 Block diagram of the ASC
register (RxBuffer)
Receive buffer
Receive shift
Run
register
Mode
StopBits
Serial port control
Reload register
Baud rate timer
Internal bus
Shift clock
Clock
register (TxBuffer)
Transmit buffer
Transmit shift
4 -input OR
register
gate
Receive buffer
full interrupt
Transmitter
empty interrupt
Transmit buffer
empty interrupt
Error
interrupt
TXD
ASC_interrupt