Megawin Technology Co., Ltd.
MG87FE/L52
Baud-Rate Generator Mode (BRG)
Timer2 can be configured to generate various baud rate. Bit TCLK and/or RCLK in T2CON allow
the serial port transmit and receive baud rates to be derived from either Timer1 or Timer2. When
TCLK=0, Timer1 is used as the serial port transmit baud rate generator. When TCLK=1, Timer2
is used as the serial port transmit baud rate generator. RCLK has the same effect for the serial
port baud rate. With these two bits, the serial port can have different receive and transmit baud
rates – one generated from Timer1 and the other from Timer2.
In BRG mode, Timer2 is operated very like auto-reload up-only mode except that the T2EX pin
can not control reload. An overflow on Timer2 will load RCAP2H, RCAP2L contents onto
Timer2 but TF2 will not be set. A 1-to-0 transition on T2EX pin can set EXF2 to request interrupt
service if EXEN2=1.
The baud rate in UART Mode-1 and Mode-3 are determined by Timer2’s overflow rate given
below:
22
Preliminary ver 1.3
Date: 2009-JAN-20
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
