Philips Semiconductors
80C51 8-bit Flash microcontroller family
4K/8K/16K/32K Flash
Preliminary data
P89C51X2/52X2/54X2/58X2
OSC
÷ n*
T2 Pin
C/T2 = 0
C/T2 = 1
CONTROL
TL2
(8-BITS)
TH2
(8-BITS)
TRANSITION
DETECTOR
TR2 RELOAD
RCAP2L
RCAP2H
TF2
T2EX PIN
CONTROL
*n = 6 in 6-clock mode; n = 12 in 12-clock mode.
EXEN2
Figure 9. Timer 2 in Auto-Reload Mode (DCEN = 0)
EXF2
TIMER 2
INTERRUPT
SU01623
(DOWN COUNTING RELOAD VALUE)
FFH
FFH
TOGGLE
EXF2
OSC
÷ n*
T2 Pin
C/T2 = 0
TL2
C/T2 = 1
CONTROL
TR2
OVERFLOW
TH2
*n = 6 in 6-clock mode; n = 12 in 12-clock mode.
RCAP2L
RCAP2H
(UP COUNTING RELOAD VALUE)
Figure 10. Timer 2 Auto Reload Mode (DCEN = 1)
TF2
COUNT
DIRECTION
1 = UP
0 = DOWN
T2EX PIN
INTERRUPT
SU01624
2002 Jun 06
18