GENERAL DESCRIPTION
The 87LPC764 is a 20-pin single-chip microcontroller designed for low pin count applications demanding high-integration, low cost solutions over a wide range of performance requirements. A member of the Philips low pin count family, the 87LPC764 offers programmable oscillator configurations for high and low speed crystals or RC operation, wide operating voltage range, programmable port output configurations, selectable Schmitt trigger inputs, LED drive outputs, and a built-in watchdog timer. The 87LPC764 is based on an accelerated 80C51 processor architecture that executes instructions at twice the rate of standard 80C51 devices.

FEATURES
• An accelerated 80C51 CPU provides instruction cycle times of
   300–600 ns for all instructions except multiply and divide when
   executing at 20 MHz. Execution at up to 20 MHz when
   VDD = 4.5 V to 6.0 V, 10 MHz when VDD = 2.7 V to 6.0 V.
• 2.7 V to 6.0 V operating range for digital functions.
• 4 kbytes EPROM code memory.
• 128 byte RAM data memory.
• 32 byte customer code EPROM allows serialization of devices,
   storage of setup parameters, etc.
• Two 16-bit counter/timers. Each timer may be configured to toggle
   a port output upon timer overflow.
• Two analog comparators.
• Full duplex UART.
• I2C communication port.
• Eight keypad interrupt inputs, plus two additional external interrupt
   inputs.
• Four interrupt priority levels.
• Watchdog timer with separate on-chip oscillator, requiring no
   external components. The watchdog timeout time is selectable
   from 8 values.
• Active low reset. On-chip power-on reset allows operation with no
   external reset components.
• Low voltage reset. One of two preset low voltage levels may be
   selected to allow a graceful system shutdown when power fails.
   May optionally be configured as an interrupt.
• Oscillator Fail Detect. The watchdog timer has a separate fully
   on-chip oscillator, allowing it to perform an oscillator fail detect
   function.
• Configurable on-chip oscillator with frequency range and RC
   oscillator options (selected by user programmed EPROM bits).
   The RC oscillator option allows operation with no external
   oscillator components.
• Programmable port output configuration options:
   quasi-bidirectional, open drain, push-pull, input-only.
• Selectable Schmitt trigger port inputs.
• LED drive capability (20 mA) on all port pins.
• Controlled slew rate port outputs to reduce EMI. Outputs have
   approximately 10 ns minimum ramp times.
• 15 I/O pins minimum. Up to 18 I/O pins using on-chip oscillator
   and reset options.
• Only power and ground connections are required to operate the
   87LPC764 when fully on-chip oscillator and reset options are
   selected.
• Serial EPROM programming allows simple in-circuit production
   coding. Two EPROM security bits prevent reading of sensitive
   application programs.
• Idle and Power Down reduced power modes. Improved wakeup
   from Power Down mode (a low interrupt input starts execution).
   Typical Power Down current is 1 µA.
• 20-pin DIP, SO, and TSSOP packages.