Features
• Compatible with MCS
®
-51
Products
• 4K Bytes of In-System Programmable (ISP) Flash Memory
– Endurance: 10,000 Write/Erase Cycles
• 2.7V to 4.0V Operating Range
• Fully Static Operation: 0 Hz to 16 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Full Duplex UART Serial Channel
• Low-power Idle and Power-down Modes
• Interrupt Recovery from Power-down Mode
• Watchdog Timer
• Dual Data Pointer
• Power-off Flag
• Flexible ISP Programming (Byte and Page Mode)
• Green (Pb/Halide-free) Packaging Option
1. Description
The AT89LS51 is a low-voltage, high-performance CMOS 8-bit microcontroller with
4K bytes of in-system programmable Flash memory. The device is manufactured
using Atmel’s high-density nonvolatile memory technology and is compatible with the
industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the pro-
gram memory to be reprogrammed in-system or by a conventional nonvolatile
memory programmer. By combining a versatile 8-bit CPU with in-system programma-
ble Flash on a monolithic chip, the Atmel AT89LS51 is a powerful microcontroller
which provides a highly-flexible and cost-effective solution to many embedded control
applications.
The AT89LS51 provides the following standard features: 4K bytes of Flash, 128 bytes
of RAM, 32 I/O lines, Watchdog timer, two data pointers, two 16-bit timer/counters, a
five-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator,
and clock circuitry. In addition, the AT89LS51 is designed with static logic for opera-
tion 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
external interrupt or hardware reset.
8-bit
Low-Voltage
Microcontroller
with 4K Bytes
In-System
Programmable
Flash
AT89LS51
3053C–MICRO–6/08
