The P83C557E6/P80C557E6 is a single-chip 8-bit microcontroller produced by Philips. It features an 80C51 central processing unit, 48K × 8 ROM, 1536 × 8 RAM, two standard 16-bit timer/counters, a 10-bit ADC, two 8-bit resolution, pulse width modulation outputs, five 8-bit I/O ports, an I2C-bus serial I/O port, full-duplex UART, on-chip watchdog timer, 15 interrupt sources, 2 priority levels, 4.5 to 5.5 V power supply range, 3.5 MHz to 16 MHz frequency range, PLL oscillator, 32 kHz reference and software-selectable system clock frequency, seconds timer, software enable/disable of ALE output pulse, electromagnetic compatibility improvements, wake-up from power-down by external or seconds interrupt
