8-bit microcontroller with accelerated two-clock 80C51 core
2.2 Additional features
A high performance 80C51 CPU provides instruction cycle times of 111 ns to 222 ns
for all instructions except multiply and divide when executing at 18 MHz. This is six
times the performance of the standard 80C51 running at the same clock frequency. A
lower clock frequency for the same performance results in power savings and reduced
Serial flash In-Circuit Programming (ICP) allows simple production coding with
commercial EPROM programmers. Flash security bits prevent reading of sensitive
Serial flash In-System Programming (ISP) allows coding while the device is mounted
in the end application.
In-Application Programming (IAP) of the flash code memory. This allows changing the
code in a running application.
Watchdog timer with separate on-chip oscillator, requiring no external components.
The watchdog prescaler is selectable from eight values.
Low voltage reset (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 from
Power-down mode (a LOW interrupt input starts execution). Typical power-down
current is 1 μA (total power-down with voltage comparators disabled).
Active-LOW reset. On-chip power-on reset allows operation without external reset
components. A reset counter and reset glitch suppression circuitry prevent spurious
and incomplete resets. A software reset function is also available.
Configurable on-chip oscillator with frequency range options selected by user
programmed flash configuration bits. Oscillator options support frequencies from
20 kHz to the maximum operating frequency of 18 MHz.
Oscillator fail detect. The watchdog timer has a separate fully on-chip oscillator
allowing it to perform an oscillator fail detect function.
Programmable port output configuration options: quasi-bidirectional, open drain,
Port ‘input pattern match’ detect. Port 0 may generate an interrupt when the value of
the pins match or do not match a programmable pattern.
LED drive capability (20 mA) on all port pins. A maximum limit is specified for the
Controlled slew rate port outputs to reduce EMI. Outputs have approximately 10 ns
minimum ramp times.
Only power and ground connections are required to operate the
P89LPC933/934/935/936 when internal reset option is selected.
Four interrupt priority levels.
Eight keypad interrupt inputs, plus two additional external interrupt inputs.
Schmitt trigger port inputs.
Second data pointer.
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 8 — 12 January 2011
© NXP B.V. 2011. All rights reserved.
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