W78E516DDG Datasheet, PDF (32/90 Pages) Nuvotem Talema – 8-BIT MICROCONTROLLER

W78E516D/W78E058D Data Sheet
Read
APROM
0000
0
0
0
Address in Data out
Timer 2 Control
Bit: 7
6
5
4
3
2
1
0
TF2
EXF2
RCLK
TCLK
EXEN2 TR2
C / T2
CP / RL2
Mnemonic: T2CON
Address: C8h
BIT NAME
FUNCTION
7 TF2
Timer 2 overflow flag: This bit is set when Timer 2 overflows. 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.
6 EXF2
Timer 2 External Flag: A negative transition on the T2EX pin (P1.1) or timer 2
overflow will cause this flag to set based on the ^{CP / RL2} , EXEN2 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.
5 RCLK
Receive Clock Flag: This bit determines the serial port 0 time-base when re-
ceiving data in serial modes 1 or 3. If it is 0, then timer 1 overflow is used for
baud rate generation, otherwise timer 2 overflow is used. Setting this bit forces
timer 2 in baud rate generator mode.
4 TCLK
Transmit Clock Flag: This bit determines the serial port 0 time-base when
transmitting data in modes 1 and 3. If it is set to 0, the timer 1 overflow is used
to generate the baud rate clock otherwise timer 2 overflow is used. Setting this
bit forces timer 2 in baud rate generator mode.
3 EXEN2
Timer 2 External Enable. This bit enables the capture/reload function on the
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, otherwise a negative transition de-
tected on the T2EX pin will result in capture or reload.
2 TR2
1 _{C / T2}
0 _{CP / RL2}
Timer 2 Run Control. This bit enables/disables the operation of timer 2. Clear-
ing this bit will halt the timer 2 and 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 used in baud rate generator mode.
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 be
ignored and the timer will function in an auto-reload mode following each over-
flow. If the bit is 0 then auto-reload will occur when timer 2 overflows or a fal-
ling edge is detected on T2EX pin if EXEN2 = 1. If this bit is 1, then timer 2
captures will occur when a falling edge is detected on T2EX pin if EXEN2 =
1.
Timer 2 Capture LSB
- 32 -