SN8F2280 Series
USB 2.0 Full-Speed 8-Bit Micro-Controller
The UART communication supports 2-byte data length. The function is for continuous data streams and immediate
data request. The 2-byte data format is a continuously byte data form. The gap between the 2-byte data is unit baud
rate. The first byte data stores in URRXD1 (receiver) and URTXD1 (transmitter). The second byte data stores in
URRXD2 (receiver) and URTXD2 (transmitter).The 2-byte data format is as following.
2-Byte Transfer Format with Parity Bit
2-Byte Transfer Format without Parity Bit
The UART supports interrupt function. UTRXIEN/UTTXIEN are UART transfer interrupt function control bit.
UTRXIEN=0, disable UART receiver interrupt function. UTTXIEN=0, disable UART transmitter interrupt function.
UTRXIEN=1, enable UART receiver interrupt function. UTTXIEN=1, enable UART transmitter interrupt function. When
UART interrupt function enable, the program counter points to interrupt vector (ORG 8) to do UART interrupt service
routine after UART operating. UTRXIRQ and UTTXIRQ are UART interrupt request flags, and also to be the UART
operating status indicator when UTRXIEN=0 or UTTXIEN=0, but cleared by program. When UART operation finished,
the UTRXIRQ/UTTXIRQ would be set to “1”.
Note: The first step of UART operation is to setup the UART pins’ mode. Enable URXEN/UTXEN to control
UART pins’ mode.
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