SN8F2280 Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
10 Universal Asynchronous
Receiver/Transmitter (UART)
10.1 OVERVIEW
The UART interface is an universal asynchronous receiver/transmitter method. The serial interface is applied to low
speed data transfer and communicate with low speed peripheral devices. The UART transceiver of Sonix 8-bit MCU
allows RS232 standard and supports one and two bytes data length. The transfer format has start bit, 8/16-bit data,
parity bit and stop bit. Programmable baud rate supports different speed peripheral devices. UART I/O pins support
push-pull and open-drain structures controlled by register.
The UART features include the following:
z
z
z
z
z
Full-duplex, 2-wire asynchronous data transfer.
Programmable baud rate.
8-bit and 16-bit data length.
Odd and even parity bit.
End-of-Transfer interrupt.
10.2 UART OPERATION
The UART RX and TX pins are shared with GPIO. When UART enables (URXEN=1, UTXEN=1), the UART shared
pins transfers to UART purpose and disable GPIO function automatically. When UART disables, the UART pins returns
to GPIO last status. The UART data buffer length supports 1-byte and 2-byte. After UART RX operation finished, the
UTRXIRQ sets as “1”. After UART TX operation finished, the UTTXIRQ sets as “1”. The UART IRQ bits are cleared by
program. If the UTRXIEN or UTTXIEN set to enable, the UTRXIRQ and UTTXIRQ triggers the interrupt request and
program counter jumps to interrupt vector to execute interrupt service routine.
UART Interface Circuit Diagram
SONiX TECHNOLOGY CO., LTD
Page 115
Version 1.1
SONIX [ SONIX TECHNOLOGY COMPANY ]
