AT89S8252 Microcontroller 24MHz 8 Bit 40 Pin

From the shop's description

The AT89S8252 is a low-power, high-performance CMOS 8-bit microcomputer with 8K bytes of downloadable Flash programmable and erasable read only memory and 2K bytes of EEPROM. 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 downloadable Flash allows the program memory to be reprogrammed in-system through an SPI serial interface or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with downloadable Flash on a monolithic chip, the Atmel AT89S8252 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. Features:- Compatible with MCS-51™ Products 8K Bytes of In-System Reprogrammable Downloadable Flash Memory SPI Serial Interface for Program Downloading Endurance: 1,000 Write/Erase Cycles 2K Bytes EEPROM Endurance: 100,000 Write/Erase Cycles 4V to 6V Operating Range Fully Static Operation: 0 Hz to 24 MHz Three-level Program Memory Lock 256 x 8-bit Internal RAM 32 Programmable I/O Lines Three 16-bit Timer/Counters Nine Interrupt Sources Programmable UART Serial Channel SPI Serial Interface Low-power Idle and Power-down Modes Interrupt Recovery From Power-down Programmable Watchdog Timer Dual Data Pointer Power-off Flag Pin Out Pin Description Pin Number Description 1 – 8 P1.0-P1.7 – Port 1 9 RESET – Reset (Active Low) 10 – 17 P3.0-P3.7 – Port 3 18 XTAL2 – Crystal 19 XTAL1 – Crystal 20 GND – Ground 21 – 28 P2.0-P2.7 – Port 2 29 PSEN – Program Store Enable 30 ALE – Address Latch Enable 31 EA – External Access Enable 32 – 39 P0.7-P0.1 – Port 0 40 Vcc – Positive Power Supply Datasheet for AT89S8252