W77C32F-40 Nuvoton Technology Corporation of America, W77C32F-40 Datasheet - Page 57

• Manufacturer Part Number: W77C32F-40
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of W77C32F-40

• Lead Free Status / Rohs Status: Supplier Unconfirmed

13.2.4 Baud Rate Generator Mode
The baud rate generator mode is enabled by setting either the RCLK or TCLK bits in T2CON register.
While in the baud rate generator mode, Timer/Counter 2 is a 16 bit counter with auto reload when the
count rolls over from FFFFh. However, rolling over does not set the TF2 bit. If EXEN2 bit is set, then a
negative transition of the T2EX pin will set EXF2 bit in the T2CON register and cause an interrupt
request.
13.2.5 Programmable Clock-out
Timer 2 is equipped with a new clock-out feature which outputs a 50% duty cycle clock on P1.0. It can
be invoked as a programmable clock generator. To configure Timer 2 with clock-out mode, software
must initiate it by setting bit T2OE = 1, C/T2 = 0 and CP/RL = 0. Setting bit TR2 will start the timer.
This mode is similar to the baud rate generator mode, it will not generate an interrupt while Timer 2
overflow. So it is possible to use Timer 2 as a baud rate generator and a clock generator at the same
time. The clock-out frequency is determined by the following equation:
The Clock-out Frequency = Oscillator Frequency / [4 X (RCAP2H, RCAP2L) ]
EXEN2 = T2CON.3
EXEN2 = T2CON.3
div. by 4
div. by 64
div. by 1024 osc/512
Mode
TR2 = T2CON.2
TR2 = T2CON.2
Clock Source
T2EX = P1.1
T2EX = P1.1
T2 = P1.0
osc/2
osc/32
input
div. by 4
div. by 64
div. by 1024 osc/512
Mode
Clock Source
osc/2
osc/32
input
Figure 18. Programmable Clock-Out Mode
Figure 17. Baud Rate Generator Mode
C/T = T2CON.1
0
1
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RCAP2L
RCAP2L
Publication Release Date: December 20, 2005
TL2
TL2
RCAP2H
RCAP2H
TH2
TH2
W77C32/W77C032
T2CON.6
T2CON.6
EXF2
EXF2
1/2
overflow
Timer 2
Interrupt
Interrupt
Timer 2
Timer 2
T2=P1.0
Revision A5