AT89S8252

• 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
• 4.0V 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

Operating Temperature................................... -55°C to +125°C
Storage Temperature ..................................... -65°C to +150°C
Voltage on Any Pin
with Respect to Ground .........................................-1.0V to +7.0V
Maximum Operating Voltage................................................. 6.6V
DC Output Current....................................................... ....15.0 mA

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

The AT89S8252 provides the following standard features: 8K bytes of Downloadable Flash, 2K bytes of EEPROM, 256 bytes of RAM, 32 I/O lines, programmable watchdog timer, two Data Pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S8252 is designed with static logic for operation 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 interrupt or hardware reset.

The Downloadable Flash AT89S8252 can be changed a single byte at a time and is accessible through the SPI serial interface. Holding RESET active forces the SPI bus into a serial programming interface and allows the program memory to be written to or read from unless Lock Bit 2 has been activated.