AT89C51RB2-3CSUL Atmel, AT89C51RB2-3CSUL Datasheet - Page 27
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AT89C51RB2-3CSUL
Manufacturer Part Number
AT89C51RB2-3CSUL
Description
MCU 8051 16K FLASH 3V 44-PLCC
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51RB2-RLTIL.pdf
(127 pages)
Specifications of AT89C51RB2-3CSUL
Core Processor
8051
Core Size
8-Bit
Speed
40MHz
Connectivity
SPI, UART/USART
Peripherals
POR, PWM, WDT
Number Of I /o
32
Program Memory Size
16KB (16K x 8)
Program Memory Type
FLASH
Ram Size
1.25K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 3.6 V
Oscillator Type
External
Operating Temperature
-40°C ~ 85°C
Package / Case
44-PLCC
Processor Series
AT89x
Core
8051
Data Bus Width
8 bit
Data Ram Size
1280 B
Interface Type
UART, SPI
Maximum Clock Frequency
60 MHz
Number Of Programmable I/os
32
Number Of Timers
3
Operating Supply Voltage
2.7 V to 5.5 V
Mounting Style
Through Hole
3rd Party Development Tools
PK51, CA51, A51, ULINK2
For Use With
AT89STK-11 - KIT STARTER FOR AT89C51RX2
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Programmable Clock-out
Mode
4180E–8051–10/06
Figure 9. Auto-Reload Mode Up/Down Counter (DCEN = 1)
In the clock-out mode, Timer 2 operates as a 50% duty-cycle, programmable clock gen-
erator (see Figure 10). The input clock increments TL2 at frequency F
timer repeatedly counts to overflow from a loaded value. At overflow, the contents of
RCAP2H and RCAP2L registers are loaded into TH2 and TL2. In this mode, Timer 2
overflows do not generate interrupts. The formula gives the clock-out frequency as a
function of the system oscillator frequency and the value in the RCAP2H and RCAP2L
registers:
For a 16 MHz system clock, Timer 2 has a programmable frequency range of 61 Hz
(F
T2 pin (P1.0).
Timer 2 is programmed for the clock-out mode as follows:
•
•
•
•
•
It is possible to use Timer 2 as a baud rate generator and a clock generator simulta-
neously. For this configuration, the baud rates and clock frequencies are not
independent since both functions use the values in the RCAP2H and RCAP2L registers.
Clock O
CLK PERIPH
F
Set T2OE bit in T2MOD register.
Clear C/T2 bit in T2CON register.
Determine the 16-bit reload value from the formula and enter it in RCAP2H/RCAP2L
registers.
Enter a 16-bit initial value in timer registers TH2/TL2. It can be the same as the
reload value or a different one depending on the application.
To start the timer, set TR2 run control bit in T2CON register.
CLK PERIPH
–
utFrequency
/2
16
)
to 4 MHz (F
=
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
4
CLK PERIPH
×
:
6
(
65536 RCAP2H RCAP2L
(UP COUNTING RELOAD VALUE)
(DOWN COUNTING RELOAD VALUE)
F
/4). The generated clock signal is brought out to
–
T2
CLKPERIPH
RCAP2L
(8-bit)
(8-bit)
(
8 -bit)
TL2
FFh
T2CON
RCAP2H
C/T2
(8-bit)
(8-bit)
TH2
(8-bit)
0
FFh
1
⁄
AT89C51RB2/RC2
T2CON
TR2
)
T2EX:
if DCEN = 1, 1 = UP
if DCEN = 1, 0 = DOWN
if DCEN = 0, up counting
TOGGLE
T2CON
TF2
CLK PERIPH
T2CON
EXF2
INTERRUPT
TIMER 2
/2. The
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