Description
The AT90S4434/8535 is a low-power CMOS 8-bit microcontroller based on the AVR® enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the AT90S4434/8535 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

Features
• Utilizes the AVR ® Enhanced RISC Architecture
• AVR - High Performance and Low Power RISC Architecture
• 118 Powerful Instructions - Most Single Clock Cycle Execution
• 8K bytes of In-System Programmable Flash AT90S/LS8535
4K bytes of In-System Programmable Flash AT90S/LS4434
– SPI Serial Interface for In-System Programming
– Endurance: 1,000 Write/Erase Cycles
• 512 bytes EEPROM AT90S/LS8535
256 bytes EEPROM AT90S/LS4434
– Endurance: 100,000 Write/Erase Cycles
• 512 bytes Internal SRAM AT90S/LS8535
256 bytes Internal SRAM AT90S/LS4434
• 8-Channel, 10-Bit ADC
• 32 x 8 General Purpose Working Registers
• 32 Programmable I/O Lines
• Programmable Serial UART
• VCC: 4.0 - 6.0V AT90S4434/AT90S8535
• VCC: 2.7 - 6.0V AT90LS4434/AT90LS8535
• Speed Grades:
0 - 8 MHz AT90S4434/AT90S8535,
0 - 4 MHz (AT90LS4434/AT90LS8535
• Power-On Reset Circuit
• Up to 8 MIPS Throughput at 8 MHz
• RTC with Separate Oscillator and Counter Mode
• Two 8-Bit Timer/Counters with Separate Prescaler and Compare Mode
• One 16-Bit Timer/Counter with Separate Prescaler and Compare and Capture Modes
• 3 PWM channels
• External and Internal Interrupt Sources
• Programmable Watchdog Timer with On-Chip Oscillator
• On-Chip Analog Comparator
• Three Sleep Modes: Idle, Power Save, and Power Down
• Programming Lock for Software Security