MEGAWIN

MLC852P Technical Summary

19

The UART function of MLC852P is half duplex. User could set UART_SETUP and UART_CTRL

registers to select the UART operating mode. An interrupt event will be generated when an Rx/Tx

operation is completed. UART_STS records the status of the operation. UART_STS is set by

hardware and cleared (all but the ‘Ring’ bit) by writing ‘1’ (writing ‘0’ has no effect) to the bits. The

UART_RBUF stores the received data in an Rx operation. Writing data into UART_TBUF would

start a Tx operation automatically. The UART_STS.Ring is a flag indicating that the UART module

is on receiving. User should not transmit data when the Ring flag is ‘1’. Besides, for the half duplex

limitation, if a receiving operation occurs during a transmitting operation, the both operations would

error.

The following figure shows the data format of the UART module.

8 bits data

priority bit, could be disabled

start bit: 0

stop bit: 1

Each frame contains 10 or 11 bits depending on priority bit disabled or enabled