W79E201 Datasheet, PDF (23/87 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E201
BIT NAME
FUNCTION
Timer 2 overflow flag: This bit is set when Timer 2 overflows. It is also set when
7
TF2
the count is equal to the capture register in down count mode. It can be set only if
RCLK and TCLK are both 0. It is cleared only by software. Software can also set
or clear this bit.
Timer 2 External Flag: A negative transition on the T2EX pin (P1.1) or timer 2
underflow/overflow will cause this flag to set based on the CP/RL2, EXEN2 and
6 EXF2 DCEN bits. If set by a negative transition, this flag must be cleared by software.
Setting this bit in software or detection of a negative transition on T2EX pin will
force a timer interrupt if enabled.
Receive clock Flag: This bit determines the serial port time-base when receiving
5
RCLK
data in serial modes 1 or 3. If it is 0, then timer 1 overflow is used for baud rate
generation, else timer 2 overflow is used. Setting this bit forces timer 2 in baud
rate generator mode.
Transmit clock Flag: This bit determines the serial port time-base when
4
TCLK
transmitting data in mode 1 and 3. If it is set to 0, the timer 1 overflow is used to
generate the baud rate clock, else timer 2 overflow is used. Setting this bit forces
timer 2 in baud rate generator mode.
Timer 2 External Enable: This bit enables the capture/reload function on the
3
EXEN2
T2EX pin if Timer 2 is not generating baud clocks for the serial port. If this bit is 0,
then the T2EX pin will be ignored, else a negative transition detected on the
T2EX pin will result in capture or reload.
2
TR2
Timer 2 Run Control: This bit enables/disables the operation of timer 2.halting this
will preserve the current count in TH2, TL2.
Counter/Timer select: This bit determines whether timer 2 will function as a timer
or a counter. Independent of this bit, the timer will run at 2 clocks per tick when
1
C/T2 ^{used in baud rate generator mode. If it is set to 0, then timer 2 operates as a timer}
at a speed depending on T2M bit (CKCON.5), else, it will count negative edges
on T2 pin.
Capture/Reload Select: This bit determines whether the capture or reload function
will be used for timer 2. If either RCLK or TCLK is set, this bit will not function and
0
the timer will function in an auto-reload mode following each overflow. If the bit is
CP/RL2 _{0 then auto-reload will occur when timer 2 overflows or a falling edge is detected}
on T2EX if EXEN2 = 1. If this bit is 1, then timer 2 captures will occur when a
falling edge is detected on T2EX if EXEN2 = 1.
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Publication Release Date: December 16, 2004
Revision A2