AT89LS51 is a low-voltage, high-performance CMOS 8-bit microcontroller produced by Atmel. It has a 4K byte on-chip programmable Flash memory that can be reprogrammed in-system or by a conventional non-volatile memory programmer. AT89LS51 also integrates 128 bytes of RAM, 32 I/O pins, watchdog timer, two data pointers, two 16-bit timers/counters, five-vector two-level interrupt architecture, low-power idle mode and power-down mode.
The AT89LS51 microcontroller offers a 4 KB in‑system programmable flash memory, 128 bytes of internal RAM, 32 programmable I/O lines, two 16‑bit timer/counters, a full‑duplex UART, watchdog timer and low‑power idle and power‑down modes. It operates from 2.7 V to 4.0 V and supports a static operation range from 0 Hz to 16 MHz, making it suitable for a wide range of embedded control applications.
The document provides detailed pin configurations for 40‑lead PDIP, 42‑lead PDIP and 44‑lead TQFP packages, a block diagram of the internal architecture, special function register maps, and mechanical dimensions for the various package types.
| Flash Memory | 4 KB |
|---|---|
| Internal RAM | 128 bytes |
| Programmable I/O Lines | 32 |
| Timer/Counters | Two 16‑bit |
| Operating Voltage | 2.7 V to 4.0 V |
| Maximum Clock Frequency | 16 MHz |
| Watchdog Timer | Present |
| Package Type | 40‑lead PDIP (also 42‑lead PDIP, 44‑lead TQFP) |
The AT89LS51 contains 4 KB of in‑system programmable flash memory.
It provides 32 programmable I/O lines.
P1.5 is MOSI, P1.6 is MISO, and P1.7 is SCK for ISP.