General description
The P89LPC9301/931A1 is a single-chip microcontroller, available in low cost packages, based on a high performance processor architecture that executes instructions in two to four clocks, six times the rate of standard 80C51 devices. Many system-level functions have been incorporated into the P89LPC9301/931A1 in order to reduce component count, board space, and system cost.

FEATUREs and benefits
Principal features
■ 4 kB/8 kB byte-erasable flash code memory organized into 1 kB sectors and 64-byte pages. Single-byte erasing allows any byte(s) to be used as non-volatile data storage.
■ 256-byte RAM data memory.
■ Two analog comparators with selectable inputs and reference source.
■ Two 16-bit counter/timers (each may be configured to toggle a port output upon timer overflow or to become a PWM output).
■ A 23-bit system timer that can also be used as real-time clock consisting of a 7-bit prescaler and a programmable and readable 16-bit timer.
■ Enhanced UART with a fractional baud rate generator, break detect, framing error detection, and automatic address detection; 400 kHz byte-wide I2C-bus communication port and SPI communication port.  2.4 V to 3.6 V VDD operating range. I/O pins are 5 V tolerant (may be pulled up or driven to 5.5 V).
■ Enhanced low voltage (brownout) detect allows a graceful system shutdown when power fails.
■ 28-pin TSSOP and PLCC packages with 23 I/O pins minimum and up to 26 I/O pins while using on-chip oscillator and reset options.