P89V51RC2FN,112 NXP Semiconductors, P89V51RC2FN,112 Datasheet - Page 33

• Manufacturer Part Number: P89V51RC2FN,112
• Description: IC 80C51 MCU FLASH 32K 40-DIP
• Manufacturer: NXP Semiconductors
• Series: 89Vr

Specifications of P89V51RC2FN,112

• Program Memory Type: FLASH
• Program Memory Size: 32KB (32K x 8)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: P89V5x
• Core: 80C51
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, UART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 622-1017 - BOARD 44-ZIF PLCC SOCKET622-1001 - USB IN-CIRCUIT PROG 80C51ISP
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 568-2430-5; 935278782112; P89V51RC2FN

NXP Semiconductors
P89V51RB2_RC2_RD2_5
Product data sheet
Fig 12. Timer 2 in Capture mode
OSC
T2 pin
6.5.2 Auto-reload mode (up or down counter)
T2EX pin
This bit can be used to generate an interrupt (by enabling the Timer 2 interrupt bit in the
IEN0 register). If EXEN2 = 1, Timer 2 operates as described above, but with the added
feature that a 1-to-0 transition at external input T2EX causes the current value in the
Timer 2 registers, TL2 and TH2, to be captured into registers RCAP2L and RCAP2H,
respectively.
In addition, the transition at T2EX causes bit EXF2 in T2CON to be set, and EXF2 like
TF2 can generate an interrupt (which vectors to the same location as Timer 2 overflow
interrupt). The Timer 2 interrupt service routine can interrogate TF2 and EXF2 to
determine which event caused the interrupt.
There is no reload value for TL2 and TH2 in this mode. Even when a capture event occurs
from T2EX, the counter keeps on counting T2 pin transitions or f
loaded contents of RCAP2L and RCAP2H registers are not protected, once Timer2
interrupt is signalled it has to be serviced before new capture event on T2EX pin occurs.
Otherwise, the next falling edge on T2EX pin will initiate reload of the current value from
TL2 and TH2 to RCAP2L and RCAP2H and consequently corrupt their content related to
previously reported interrupt.
In the 16-bit auto-reload mode, Timer 2 can be configured as either a timer or counter (via
C/T2 in T2CON), then programmed to count up or down. The counting direction is
determined by bit DCEN (Down Counter Enable) which is located in the T2MOD register
(see
counting up. If the DCEN bit is set, Timer 2 can count up or down depending on the value
of the T2EX pin.
Figure 13
6
transition
detector
Table 22
C/T2 = 0
C/T2 = 1
shows Timer 2 counting up automatically (DCEN = 0).
and
EXEN2
Table
control
Rev. 05 — 12 November 2009
TR2
23). When reset is applied, DCEN = 0 and Timer 2 will default to
control
capture
RCAP2L RCAP2H
(8-bits)
TL2
(8-bits)
P89V51RB2/RC2/RD2
TH2
8-bit microcontrollers with 80C51 core
EXF2
TF2
osc
/ 6 pulses. Since once
© NXP B.V. 2009. All rights reserved.
002aaa523
interrupt
timer 2
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