AT89C51RC-24JC Atmel, AT89C51RC-24JC Datasheet - Page 17
![IC MICRO CTRL 24MHZ 44PLCC](/photos/6/70/67043/453-44-plcc_sml.jpg)
AT89C51RC-24JC
Manufacturer Part Number
AT89C51RC-24JC
Description
IC MICRO CTRL 24MHZ 44PLCC
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51RC-24PU.pdf
(36 pages)
Specifications of AT89C51RC-24JC
Core Processor
8051
Core Size
8-Bit
Speed
24MHz
Connectivity
SPI, UART/USART
Peripherals
WDT
Number Of I /o
32
Program Memory Size
32KB (32K x 8)
Program Memory Type
FLASH
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
4 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
0°C ~ 70°C
Package / Case
44-PLCC
For Use With
AT89STK-11 - KIT STARTER FOR AT89C51RX2
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Eeprom Size
-
Data Converters
-
Other names
AT89C51RC24JC
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
15. Programmable Clock Out
1920D–MICRO–6/08
rupt. Note too, that if EXEN2 is set, a 1-to-0 transition in T2EX will set EXF2 but will not cause a
reload from (RCAP2H, RCAP2L) to (TH2, TL2). Thus when Timer 2 is in use as a baud rate gen-
erator, T2EX can be used as an extra external interrupt.
Note that when Timer 2 is running (TR2 = 1) as a timer in the baud rate generator mode, TH2 or
TL2 should not be read from or written to. Under these conditions, the Timer is incremented
every state time, and the results of a read or write may not be accurate. The RCAP2 registers
may be read but should not be written to, because a write might overlap a reload and cause
write and/or reload errors. The timer should be turned off (clear TR2) before accessing the Timer
2 or RCAP2 registers.
A 50% duty cycle clock can be programmed to come out on P1.0, as shown in
pin, besides being a regular I/O pin, has two alternate functions. It can be programmed to input
the external clock for Timer/Counter 2 or to output a 50% duty cycle clock ranging from 61 Hz to
4 MHz at a 16 MHz operating frequency.
To configure the Timer/Counter 2 as a clock generator, bit C/T2 (T2CON.1) must be cleared and
bit T2OE (T2MOD.1) must be set. Bit TR2 (T2CON.2) starts and stops the timer.
The clock-out frequency depends on the oscillator frequency and the reload value of Timer 2
capture registers (RCAP2H, RCAP2L), as shown in the following equation.
In the clock-out mode, Timer 2 roll-overs will not generate an interrupt. This behavior is similar to
when Timer 2 is used as a baud-rate generator. It is possible to use Timer 2 as a baud-rate gen-
erator and a clock generator simultaneously. Note, however, that the baud-rate and clock-out
frequencies cannot be determined independently from one another since they both use
RCAP2H and RCAP2L.
Figure 15-1. Timer 2 in Clock-Out Mode
(T2EX)
P1.0
P1.1
(T2)
OSC
TRANSITION
DETECTOR
Clock-Out Frequency
÷2
EXEN2
=
------------------------------------------------------------------------------------ -
4 x [65536-(RCAP2H,RCAP2L)]
C/T2 BIT
Oscillator Frequency
EXF2
TR2
÷2
TIMER 2
INTERRUPT
(8-BITS)
RCAP2L RCAP2H
TL2
AT89C51RC
T2OE (T2MOD.1)
(8-BITS)
TH2
Figure
15-1. This
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