Single-cycle microcontroller with 8KB ISP flash, 12-clock compatibility mode, 256 bytes flash data memory, 256 bytes RAM, three timers, UART, WDT, up to 36 I/Os, and an internal RC oscillator.

Key Features:

• 100% software and timing compatibility with AT89S52, meaning no changes to existing software, including fetching from external ROM or read/write from/to external RAM.
• Disable compatibility mode to achieve on average 9 times more throughput at the same current consumption and frequency as AT89S52; or lower the clock frequency 9 times and achieve the same speed as AT89S52 but with more than 5 times less current consumption.
• Save even more power and the cost of the quartz crystal altogether by using the internal 1.8432 MHz RC oscillator, which is Vcc and temperature compensated well enough to ensure proper UART serial communications. Together with the built-in POR and the BOD circuits, which ensure proper reset control, you do not need any external components for AT89LP52 to provide the reset and clock functions.
• The AT89LP52 UART can function as an almost complete master SPI port or can improve software emulation of TWI.
• Use In-Application Programming with fast page programming to alter the built-in 8K Flash program memory while executing the application, in effect making it possible to have programmable data tables embedded in the program code. Expert users can create self-modifying code with this feature.