The P89LPC952/954 are single-chip microcontrollers, 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 P89LPC952/954 in order to reduce component count, board space, and system cost.
Features
Principal features
8 kB/16 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 and a 256-byte auxiliary on-chip RAM.
8-input multiplexed 10-bit ADC with window comparator that can generate an interrupt for in or out of range results. 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) and a 23-bit system timer that can also be used as a RTC.
Two enhanced UARTs 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.
High-accuracy internal RC oscillator option, with clock doubler option, allows operation without external oscillator components. The RC oscillator option is selectable and fine tunable. Fast switching between the internal RC oscillator and any oscillator source provides optimal support of minimal power active mode with fast switching to maximum performance.
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).
44-pin packages with 40 I/O pins minimum while using on-chip oscillator and reset options.
Port 5 has high current sourcing/sinking (20 mA) for all Port 5 pins. All other port pins have high sinking capability (20 mA). A maximum limit is specified for the entire chip.
Watchdog timer with separate on-chip oscillator, requiring no external components.The watchdog prescaler is selectable from eight values.
Additional features
A high performance 80C51 CPU provides instruction cycle times of 111 ns to 222 nsfor all instructions except multiply and divide when executing at 18 MHz. This is sixtimes the performance of the standard 80C51 running at the same clock frequency. Alower clock frequency for the same performance results in power savings and reducedEMI.
Serial flash In-Circuit Programming (ICP) allows simple production coding withcommercial EPROM programmers. Flash security bits prevent reading of sensitiveapplication programs.
Serial flash In-System Programming (ISP) allows coding while the device is mountedin the end application.
In-Application Programming (IAP) of the flash code memory. This allows changing thecode in a running application.
Low voltage (brownout) detect allows a graceful system shutdown when power fails.May optionally be configured as an interrupt.
Idle and two different power-down reduced power modes. Improved wake-up fromPower-down mode (a LOW interrupt input starts execution). Typical power-downcurrent is 1 uA (total power-down with voltage comparators disabled).
Active-LOW reset input can be driven by any internal reset. On-chip power-on resetallows operation without external reset components. A reset counter and reset glitchsuppression circuitry prevent spurious and incomplete resets. A software resetfunction is also available.
Only power and ground connections are required to operate the P89LPC952/954 wheninternal reset option is selected.
Configurable on-chip oscillator with frequency range options selected by userprogrammed flash configuration bits. Oscillator options support frequencies from20 kHz to the maximum operating frequency of 18 MHz.
Oscillator fail detect. The watchdog timer has a separate fully on-chip oscillatorallowing it to perform an oscillator fail detect function.
Programmable port output configuration options: quasi-bidirectional, open drain,push-pull, input-only.
Port ´input pattern match´ detect. Port 0 may generate an interrupt when the value ofthe pins match or do not match a programmable pattern.
Controlled slew rate port outputs to reduce EMI. Outputs have approximately 10 nsminimum ramp times.
Four interrupt priority levels.
Eight keypad interrupt inputs, plus two additional external interrupt inputs.
