Datasheet
Philips Semiconductors Product specification
8XC54/58
8XC51FA/FB/FC/80C51FA
8XC51RA+/RB+/RC+/RD+/80C51RA+
80C51 8-bit microcontroller family
8K–64K/256–1K OTP/ROM/ROMless, low voltage (2.7V–5.5V),
low power, high speed (33MHz)
2000 Aug 07
16
OSC
÷ 12
C/T2 = 0
C/T2
= 1
TR2
CONTROL
TL2
(8-BITS)
TH2
(8-BITS)
TF2
RCAP2L RCAP2H
EXEN2
CONTROL
EXF2
TIMER 2
INTERRUPT
T2EX PIN
TRANSITION
DETECTOR
T2 PIN
RELOAD
SU00067
Figure 4. Timer 2 in Auto-Reload Mode (DCEN = 0)
÷12
C/T2 = 0
C/T2
= 1
TL2 TH2
TR2
CONTROL
T2 PIN
SU00730
FFH FFH
RCAP2L RCAP2H
(UP COUNTING RELOAD VALUE) T2EX PIN
TF2
INTERRUPT
COUNT
DIRECTION
1 = UP
0 = DOWN
EXF2
OVERFLOW
(DOWN COUNTING RELOAD VALUE)
TOGGLE
OSC
Figure 5. Timer 2 Auto Reload Mode (DCEN = 1)