Datasheet

ADuC845/ADuC847/ADuC848 Data Sheet
Rev. C | Page 78 of 108
T2CON—Timer/Counter 2 Control Register
SFR Address: C8H
Power-On Default: 00H
Bit Addressable: Yes
Table 52. T2CON SFR Bit Designations
Bit No. Name Description
7
TF2
Timer 2 Overflow Flag.
Set by hardware on a Timer 2 overflow. TF2 cannot be set when either RCLK = 1 or TCLK = 1.
Cleared by user software.
6 EXF2 Timer 2 External Flag.
Set by hardware when either a capture or reload is caused by a negative transition on T2EX and EXEN2 = 1.
Cleared by user software.
5 RCLK Receive Clock Enable Bit.
Set by the user to enable the serial port to use Timer 2 overflow pulses for its receive clock in serial port Modes 1 and 3.
Cleared by the user to enable Timer 1 overflow to be used for the receive clock.
4 TCLK Transmit Clock Enable Bit.
Set by the user to enable the serial port to use Timer 2 overflow pulses for its transmit clock in serial port Modes 1 and 3.
Cleared by the user to enable Timer 1 overflow to be used for the transmit clock.
3 EXEN2 Timer 2 External Enable Flag.
Set by the user to enable a capture or reload to occur as a result of a negative transition on T2EX if Timer 2 is not being
used to clock the serial port.
Cleared by the user for Timer 2 to ignore events at T2EX.
2 TR2 Timer 2 Start/Stop Control Bit.
Set by the user to start Timer 2.
Cleared by the user to stop Timer 2.
1 CNT2 Timer 2 Timer or Counter Function Select Bit.
Set by the user to select the counter function (input from external T2 pin).
Cleared by the user to select the timer function (input from on-chip core clock).
0
CAP2
Timer 2 Capture/Reload Select Bit.
Set by the user to enable captures on negative transitions at T2EX if EXEN2 = 1.
Cleared by the user to enable autoreloads with Timer 2 overflows or negative transitions at T2EX when EXEN2 = 1.
When either RCLK = 1 or TCLK = 1, this bit is ignored and the timer is forced to autoreload on Timer 2 overflow.
Timer/Counter 2 Data Registers
Timer/Counter 2 also has two pairs of 8-bit data registers
associated with it. These are used as both timer data registers
and as timer capture/reload registers.
TH2 and TL2—Timer 2 data high byte and low byte.
SFR Address: CDH and CCH respectively.
Power-On Default: 00H and 00H, respectively.
RCAP2H and RCAP2L—Timer 2 capture/reload byte and low
byte.
SFR Address: CBH and CAH, respectively.
Power-On Default: 00H and 00H, respectively.