P89C51X2/52X2/54X2/58X2 80C51 8-bit Flash Microcontroller Family 4K/8K/16K/32K Flash 128B/256B RAM

The Philips Microcontrollers described in this data sheet are high-performance static 80C51 designs. They are manufactured in an advanced CMOS process and contain a non-volatile Flash program memory. They support both 12-clock and 6-clock operation. The P89C51X2 and P89C58X2 P89C54X2 P89C52X2 P89C51X2 contain 128 byte RAM and 256 byte RAM respectively, 32 I/O lines, three 16-bit Counter Timers a six-source, four-priority level nested interrupt structure, a serial I/O port for either multi-processor Communications I/O expansion or full duplex UART and on-chip Oscillator and Clock circuits. In addition, the devices are static designs which offer a wide range of operating frequencies down to zero. Two software selectable modes of power reduction - idle mode and power-down mode - are available. The idle mode freezes the CPU while allowing the RAM, Timers serial port, and interrupt system to continue functioning. The power-down mode saves the RAM contents but freezes the Oscillator causing all other chip functions to be inoperative. Since the design is static, the Clock CAN be stopped without loss of user data. Then the execution CAN be resumed from the point the Clock was stopped.
By NXP Semiconductors