The Microchip AT89LP52 8-bit microcontroller has 4K/8 Kbytes of In-System Programmable Flash program memory and 256 bytes of Flash data memory. It operates on 2.4V to 5.5V power supply. The controller is built around an enhanced CPU core that can fetch a single byte from memory every clock cycle. In the classic 8051 architecture, each fetch requires 6 clock cycles, forcing instructions to execute in 12, 24 or 48 clock cycles. It features 4K/8K bytes of In-System Programmable Flash program memory, 256 bytes of Flash data memory, 256 bytes of RAM, up to 36 I/O lines, three 16-bit timer/counters, a programmable watchdog timer, a full-duplex serial port, an on-chip crystal oscillator, an internal 1.8432 MHz auxiliary oscillator, and a four-level, six-vector interrupt system.

100% software and timing compatibility with AT89S52
Can function as an almost complete master SPI port or can improve software emulation of TWI
Disable compatibility mode to achieve on average 9 times more throughput at the same current consumption and frequency as AT89S52