mpc82g516a Megawin Technology, mpc82g516a Datasheet - Page 47

• Manufacturer Part Number: mpc82g516a
• Description: 8-bit Microcontroller
• Manufacturer: Megawin Technology

Figure 11-7. Timer 2 in Auto-Reload Mode (DCEN=0)
Figure 11-8. Timer 2 in Auto-Reload Mode (DCEN=1)
11.2.3 Baud Rate Generator Mode
Bits TCLK and/or RCLK in T2CON register allow the serial port transmit and receive baud rates to be derived
from either Timer 1 or Timer 2. When TCLK=0, Timer 1 is used as the serial port transmit baud rate generator.
When TCLK= 1, Timer 2 is used as the serial port transmit baud rate generator. RCLK has the same effect for the
serial port receive baud rate. With these two bits, the serial port can have different receive and transmit baud
rates – one generated by Timer 1, the other by Timer 2.
Figure 11-9 shows the Timer 2 in baud rate generation mode. The baud rate generation mode is like the auto-
reload mode, in that a rollover in TH2 causes the Timer 2 registers to be reloaded with the 16-bit value in
registers RCAP2H and RCAP2L, which are preset by software.
The baud rates in modes 1 and 3 are determined by Timer 2’s overflow rate given below:
The timer can be configured for either “Timer” or “Counter” operation. In many applications, it is configured for
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* Fosc is the system clock.
T2EX Pin
T2 Pin
(P1.0)
* Fosc is the system clock.
Fosc
(P1.1)
T2 Pin
(P1.0)
Fosc
Mode 1 and 3 Baud Rates =
12
Transition
Detector
12
"0"
"1"
C/-T2
"0"
"1"
C/-T2
EXEN2
TR2
TR2
Timer 2 Overflow Rate
MPC82G516A Data Sheet
Reload
Down Counting Reload Value
Up Counting Reload Value
RCAP2L RCAP2H
16
(8 Bits)
RCAP2L RCAP2H
TL2
(8 Bits)
FFH
TL2
(8 Bits)
TH2
FFH
(8 Bits)
TH2
Reload
Reload
Overflow
Overflow
T2EX Pin
(P1.1)
EXF2
TF2
Counting Direction:
1 = Up
0 = Down
Toggle
TF2
MEGAWIN
Timer 2
Interrupt
EXF2
Timer 2
Interrupt