AT89C55WD-33AC ATMEL Corporation, AT89C55WD-33AC Datasheet - Page 14

• Manufacturer Part Number: AT89C55WD-33AC
• Description: 8-bit Microcontroller with 20K Bytes Flash
• Manufacturer: ATMEL Corporation

Figure 7. Timer 2 Auto Reload Mode (DCEN = 1)
Figure 8. Timer 2 in Baud Rate Generator Mode
14
T2EX PIN
OSC
OSC
AT89C55WD
T2 PIN
T2 PIN
÷
12
÷
2
TRANSITION
DETECTOR
NOTE: OSC. FREQ. IS DIVIDED BY 2, NOT 12
C/T2 = 0
C/T2 = 1
C/T2 = 0
C/T2 = 1
TR2
EXEN2
CONTROL
TR2
(DOWN COUNTING RELOAD VALUE)
CONTROL
CONTROL
(UP COUNTING RELOAD VALUE)
RCAP2H
0FFH
TH2
RCAP2H
TH2
EXF2
RCAP2L
0FFH
RCAP2L
TL2
TL2
OVERFLOW
INTERRUPT
TIMER 2
T2EX PIN
÷
2
"1"
"1"
TIMER 1 OVERFLOW
COUNT
DIRECTION
1=UP
0=DO
"0"
"0"
"0"
TOGGLE
"1"
INTERRUPT
TIMER 2
÷
÷
SMOD1
RCLK
TCLK
16
TF2
16
1921B–MICRO–09/02
CLOCK
CLOCK
EXF2
Rx
Tx