AT89LP51RB2 Atmel Corporation, AT89LP51RB2 Datasheet - Page 87

• Manufacturer Part Number: AT89LP51RB2
• Manufacturer: Atmel Corporation

Specifications of AT89LP51RB2

• Max. Operating Frequency: 20 MHz
• Cpu: 8051-1C
• Max I/o Pins: 42
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Adc Channels: 7
• Adc Resolution (bits): 10
• Adc Speed (ksps): 153.8
• Sram (kbytes): 1.375
• Self Program Memory: API
• Operating Voltage (vcc): 2.4 to 5.5
• Timers: 4
• Isp: SPI/OCD/UART
• Watchdog: Yes

14. Timer 2
3722A–MICRO–10/11
Figure 13-10. Timer/Counter 0 PWM Mode 3
The AT89LP51RB2/RC2/IC2 includes a 16-bit Timer/Counter 2 with the following features:
Timer 2 is a 16-bit Timer/Counter that can operate as either a timer or an event counter. The
type of operation is selected by bit C/T2 in the SFR T2CON. Timer 2 has three operating modes:
capture, auto-reload (up or down counting), and baud rate generator. The modes are selected
by bits in T2CON and T2MOD, as shown in
Timer 2 consists of two 8-bit registers, TH2 and TL2. In the Timer function, the register is incre-
mented every clock cycle. The timer rate can be prescaled by a value between 1 and 16 using
the Timer Prescaler (see
enabled and TPS defaults to 5, so Timer 2 counts every six clock cycles (1/12 of the oscillator
frequency in X1 mode or 1/6 of the oscillator frequency in X2 mode). In X2 mode Timer 2 can be
set to the X1 rate by setting the T2X2 bit in CKCON1. In Fast mode the prescaler is not enabled
by default so the count rate is equal to the system frequency (1/2 of the oscillator frequency in
X1 mode or equal to the oscillator frequency in X2 mode). In this case setting the T2X2 bit in
CKCON1 enables the prescaler for Timer 2.
Note that Timer 2 is not affected by the prescaler when operating in the Baud-Rate or Frequency
Generator modes.
• 16-bit timer/counter with one 16-bit reload/capture register
• One external reload/capture input
• Up/Down counting mode with external direction control
• UART baud rate generation
• Output-pin toggle on timer overflow
INT0 Pin
GATE0
CLK
CLK
TR0
SYS
SYS
Section 6.9 on page
TR1
AT89LP51RB2/RC2/IC2 Preliminary
÷TPS
÷TPS
Control
Table
48). In Compatibility mode the prescaler is always
14-1.
(8 Bits)
(8 Bits)
(8 Bits)
(8 Bits)
OCR0
OCR1
RL0
RH0
TL0
TH0
=
=
T0
T1
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