AT89S2051 Atmel Corporation, AT89S2051 Datasheet - Page 4

• Manufacturer Part Number: AT89S2051
• Manufacturer: Atmel Corporation

Specifications of AT89S2051

• Flash (kbytes): 2 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 15
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 2
• Isp: SPI

4.5
4.6
4.7
5.
4
Characteristics
RST
XTAL1
XTAL2
AT89S2051/S4051
Reset input. Holding the RST pin high for two machine cycles while the is running resets the
device.
Each machine cycle takes 6 or clock cycles.
Input to the inverting amplifier and input to the internal clock operating circuit.
Output from the inverting amplifier.
XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be
configured for use as an on-chip , as shown in
onator may be used. To drive the device from an external clock source, XTAL2 should be left
unconnected while XTAL1 is driven as shown in
duty cycle of the external clock signal, since the input to the internal clocking circuitry is through
a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications
must be observed.
Figure 5-1.
Note:
Figure 5-2.
C1, C2 = 5 pF ± 5 pF for Crystals
External Clock Drive Configuration
Connections
= 5 pF ± 5 pF for Ceramic Resonators
Figure
Figure
5-1. Either a quartz crystal or ceramic res-
5-2. There are no requirements on the
3390E–MICRO–6/08