AT89C55WD
Table 12-2. T2MOD – Timer 2 Mode Control Register
T2MOD Address = 0C9H
Not Bit Addressable
–
–
–
–
–
Bit
7
6
5
4
3
Reset Value = XXXX XX00B
–
T2OE
DCEN
2
1
0
Symbol
–
T2OE
DCEN
Function
Not implemented, reserved for future
Timer 2 Output Enable bit
When set, this bit allows Timer 2 to be configured as an up/down counter
Figure 12-3. Timer 2 Auto Reload Mode (DCEN = 1)
(DOWN COUNTING RELOAD VALUE)
0FFH
0FFH
TOGGLE
EXF2
OSC
÷ 12
T2 PIN
C/T2 = 0
C/T2 = 1
OVERFLOW
TH2
TL2
CONTROL
TR2
TF2
TIMER 2
INTERRUPT
RCAP2H RCAP2L
(UP COUNTING RELOAD VALUE)
COUNT
DIRECTION
1=UP
0=DO
T2EX PIN
13
1921D–MICRO–6/08