AT89C4051-24PI

AT89C4051-24PI Datasheet


The AT89C4051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read-only memory PEROM . The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C4051 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.

Part Datasheet
AT89C4051-24PI AT89C4051-24PI AT89C4051-24PI (pdf)
Related Parts Information
AT89C4051-24SI AT89C4051-24SI AT89C4051-24SI
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AT89C4051-24PC AT89C4051-24PC AT89C4051-24PC
AT89C4051-12PI AT89C4051-12PI AT89C4051-12PI
AT89C4051-12SC AT89C4051-12SC AT89C4051-12SC
AT89C4051-12SI AT89C4051-12SI AT89C4051-12SI
AT89C4051-24SC AT89C4051-24SC AT89C4051-24SC
PDF Datasheet Preview
• Compatible with Products
• 4K Bytes of Reprogrammable Flash Memory
• Endurance 1,000 Write/Erase Cycles
• 2.7V to 6V Operating Range
• Fully Static Operation 0 Hz to 24 MHz
• Two-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 15 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial UART Channel
• Direct LED Drive Outputs
• On-chip Analog Comparator
• Low-power Idle and Power-down Modes
• Brown-out Detection

The AT89C4051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read-only memory PEROM . The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C4051 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.

The AT89C4051 provides the following standard features 4K bytes of Flash, 128 bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five-vector, two-level interrupt architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C4051 is designed with static logic for operation down to zero frequency and supports two software-selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The power-down mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.
8-bit Microcontroller with 4K Bytes Flash

AT89C4051

Pin Configuration

PDIP/SOIC

RST/VPP 1 RXD P3.0 2 TXD P3.1 3

XTAL2 4 XTAL1 5 INT0 P3.2 6 INT1 P3.3 7 TO P3.4 8 T1 P3.5 9

GND 10
20 VCC 19 P1.7 18 P1.6 17 P1.5 16 P1.4 15 P1.3 14 P1.2 13 P1.1 AIN1 12 P1.0 AIN0 11 P3.7

Block Diagram
2 AT89C4051

Pin Description

VCC GND

Port 1

Port 3

RST XTAL1 XTAL2

AT89C4051

Supply voltage.

Ground.

Port 1 is an 8-bit bi-directional I/O port. Port pins P1.2 to P1.7 provide internal pullups. P1.0 and P1.1 require external pullups. P1.0 and P1.1 also serve as the positive input AIN0 and the negative input AIN1 , respectively, of the on-chip precision analog comparator. The Port 1 output buffers can sink 20 mA and can drive LED displays directly. When 1s are written to Port 1 pins, they can be used as inputs. When pins P1.2 to P1.7 are used as inputs and are externally pulled low, they will source current IIL because of the internal pullups.

Port 1 also receives code data during Flash programming and verification.

Port 3 pins P3.0 to P3.5, P3.7 are seven bi-directional I/O pins with internal pullups. P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a general purpose I/O pin. The Port 3 output buffers can sink 20 mA. When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current IIL because of the pullups.

Port 3 also serves the functions of various special features of the AT89C4051 as listed below:

Port Pin P3.0 P3.1 P3.2 P3.3 P3.4 P3.5

Alternate Functions RXD serial input port TXD serial output port INT0 external interrupt 0 INT1 external interrupt 1 T0 timer 0 external input T1 timer 1 external input

Port 3 also receives some control signals for Flash programming and verification.

Reset input. All I/O pins are reset to 1s as soon as RST goes high. Holding the RST pin high for two machine cycles while the oscillator is running resets the device.

Each machine cycle takes 12 oscillator or clock cycles.

Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

Output from the inverting oscillator amplifier.

Oscillator Characteristics

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure There are no requirements on the 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 Oscillator Connections

Note C1, C2= 30 pF ± 10 pF for Crystals = 40 pF ± 10 pF for Ceramic Resonators

Figure External Clock Drive Configuration
4 AT89C4051

AT89C4051

Special Function Registers

A map of the on-chip memory area called the Special Function Register SFR space is shown in the table below.
Ordering Information

Speed MHz

Power Supply
2.7V to 6.0V
4.0V to 6.0V
Ordering Code

AT89C4051-12PC AT89C4051-12SC

AT89C4051-12PI AT89C4051-12SI

AT89C4051-24PC AT89C4051-24SC

AT89C4051-24PI AT89C4051-24SI

Package
20P3 20S
20P3 20S
20P3 20S
20P3 20S

Operation Range

Commercial 0°C to 70°C

Industrial -40°C to 85°C

Commercial 0°C to 70°C

Industrial -40°C to 85°C
20P3 20S

Package Type 20-lead, Wide, Plastic Dual In-line Package PDIP 20-lead, Wide, Plastic Gull Wing Small Outline SOIC
16 AT89C4051

Packaging Information
20P3, 20-lead, Wide, Plastic Dual Inline Package PDIP Dimensions in Inches and Millimeters

JEDEC STANDARD MS-001 AD

SEATING PLANE
0 REF 15

AT89C4051
20S, 20-lead, Wide, Plastic Gull WIng Small Outline SOIC Dimensions in Inches and Millimeters

PIN 1
0 REF

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e-mail

Web Site

BBS 1- 408 436-4309
More datasheets: TSL2014 | 2856 | CDBV120-G | CDBV140-G | AT89C4051-24SI | AT89C4051-12PC | AT89C4051-24PC | AT89C4051-12PI | AT89C4051-12SC | AT89C4051-12SI


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Datasheet ID: AT89C4051-24PI 519079