AT89S52-24JU Atmel, AT89S52-24JU Datasheet - Page 16

• Manufacturer Part Number: AT89S52-24JU
• Description: IC MCU 8K FLASH 24MHZ 44-PLCC
• Manufacturer: Atmel
• Series: 89Sr

Specifications of AT89S52-24JU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 24MHz
• Connectivity: UART/USART
• Peripherals: WDT
• Number Of I /o: 32
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Package: 44PLCC
• Device Core: 8051
• Family Name: 89S
• Maximum Speed: 24 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 32
• Interface Type: UART
• Number Of Timers: 3
• Processor Series: AT89x
• Core: 8051
• Data Ram Size: 256 B
• Maximum Clock Frequency: 33 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89ISP
• Minimum Operating Temperature: - 40 C
• Eeprom Memory: 0 Bytes
• Input Output: 32
• Interface: UART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin PLCC
• Programmable Memory: 8K Bytes
• Timers: 3-16-bit
• Voltage, Range: 4-5.5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Figure 11-1. Timer 2 in Baud Rate Generator Mode
12. Programmable Clock Out
16
T2EX PIN
AT89S52
OSC
T2 PIN
÷
2
TRANSITION
DETECTOR
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 (for 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.
NOTE: OSC. FREQ. IS DIVIDED BY 2, NOT 12
C/T2 = 0
C/T2 = 1
Clock-Out Frequency
EXEN2
TR2
CONTROL
CONTROL
RCAP2H
TH2
EXF2
=
RCAP2L
------------------------------------------------------------------------------------ -
4 x [65536-(RCAP2H,RCAP2L)]
TL2
Oscillator Frequency
INTERRUPT
TIMER 2
÷
2
"1"
"1"
TIMER 1 OVERFLOW
"0"
"0"
"0"
"1"
÷
÷
SMOD1
RCLK
TCLK
16
16
Figure
1919D–MICRO–6/08
CLOCK
CLOCK
Rx
Tx
12-1. This