PIC16C56-LPI/P - 8-bit CMOS MCU, 1KB EPROM, 18-PDIP | Microchip
MPN: PIC16C56-LPI/P β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.69 | $1.69 |
| 10 | $1.52 | $15.20 |
| 100 | $1.36 | $136.00 |
| 500 | $1.22 | $610.00 |
| 1,000 | $1.09 | $1,090.00 |
PIC16C56-LPI/P Overview
A microcontroller (MCU) is an integrated circuit that combines a CPU core, program memory, RAM, and peripherals on a single die. The PIC16C56-LPI/P belongs to the 8-bit microcontroller hierarchy: microcontroller -> RISC MCU -> CMOS EPROM MCU -> PIC16C5X family. EPROM-based MCUs are one-shot programmable devices widely used in volume production where the program is finalized at manufacturing time, offering a lower unit cost than Flash-based parts.
Key features include seven or eight special-function hardware registers, a two-level deep hardware stack, and direct, indirect, and relative addressing modes for both data and instructions. An 8-bit real-time clock/counter (TMR0) supports timing, event counting, and simple PWM generation. The 12-bit instruction word enables a compact opcode set that yields efficient code density for control-oriented tasks.
The architecture is implemented in CMOS technology with EPROM program memory, providing low power consumption and non-volatile code storage. The RISC pipeline and Harvard-style separate program/data buses allow most instructions to execute in a single instruction cycle, giving predictable timing suitable for control loops and state machines.
Typical applications include appliance control, sensor interfacing, low-cost consumer electronics, industrial timers, and simple motor or relay drivers. The 12 I/O pins can be allocated to digital inputs, digital outputs, or TMR0-related functions such as external clock input and timer overflow output.
When designing with this device, note that EPROM parts are windowed for UV erasure and are not in-system programmable; design firmware carefully before committing to masked silicon. The two-level hardware stack limits nested subroutine depth to two levels, so deeply nested C-style code requires careful refactoring into a flat call structure.
This page synthesizes distributor pricing, parametric comparison with same-family parts, and practical design considerations not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C56-LPI/P β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16C56-LPI/P (same form factor and footprint) β differing in Package, Timers, Program Memory Size, Program Memory Type, Core.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C56-LPE/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56-LP/P
β Drop-Inβ In Stock
$3.39 / Unit
View Datasheet βPIC16C56A-04E/P
β Drop-Inβ In Stock
$1.21 / Unit
View Datasheet βPIC16C56A-04I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56A-20I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56A-20E/P
β Drop-Inβ In Stock
$2.85 / Unit
View Datasheet βPIC16C55-LP/P
β Drop-Inβ In Stock
$1.45 / Unit
View Datasheet βPIC16F54-I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56-LPI/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5X 8-bit RISC |
| Program Memory Type | EPROM (one-time programmable) |
| Program Memory Size | 1 KB (12-bit instruction width) |
| RAM Size | 25 bytes |
| I/O Pins | 12 |
| Supply Voltage | 3.3 V / 5 V |
| Package | 18-pin PDIP (through-hole) |
| Temperature Grade | Industrial (-40C to +85C) |
| Stack Depth | 2 levels (hardware) |
| Timers | TMR0 8-bit timer/counter |
| Addressing Modes | Direct, indirect, relative |
| Instruction Set Width | 12-bit |
| Data Path Width | 8-bit |
| Special-Function Registers | 7 to 8 hardware registers |
| RoHS Status | Compliant |
PIC16C56-LPI/P Pin Configuration
| Pin 1 | RA2 β Port A bit 2 (bidirectional digital I/O) |
| Pin 2 | RA3 β Port A bit 3 (bidirectional digital I/O) |
| Pin 3 | RTCC β TMR0 real-time clock/counter input |
| Pin 4 | MCLR β Master clear reset input (active low) |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0 β Port B bit 0 (bidirectional digital I/O) |
| Pin 7 | RB1 β Port B bit 1 (bidirectional digital I/O) |
| Pin 8 | RB2 β Port B bit 2 (bidirectional digital I/O) |
| Pin 9 | RB3 β Port B bit 3 (bidirectional digital I/O) |
| Pin 10 | RB4 β Port B bit 4 (bidirectional digital I/O) |
| Pin 11 | RB5 β Port B bit 5 (bidirectional digital I/O) |
| Pin 12 | RB6 β Port B bit 6 (bidirectional digital I/O) |
| Pin 13 | RB7 β Port B bit 7 (bidirectional digital I/O) |
| Pin 14 | VDD β Positive supply (3.3V or 5V) |
| Pin 15 | OSC2 β Oscillator output (crystal/ceramic/resistor) |
| Pin 16 | OSC1 β Oscillator input (crystal/ceramic/resistor) |
| Pin 17 | RA0 β Port A bit 0 (bidirectional digital I/O) |
| Pin 18 | RA1 β Port A bit 1 (bidirectional digital I/O) |
Typical Applications
PIC16C56-LPI/P is suitable for 6 applications: Appliance Control, Industrial Timer and Counter Modules, Sensor Interface and Signal Conditioning, Consumer Electronics Remote Controls, LED Display Drivers and Chasers, Educational and Hobbyist Projects.
Appliance Control
The PIC16C56-LPI/P fits appliance control boards where simple on/off sequencing, timer-based delays, and keypad/LED interfacing drive the design. Its 12 I/O pins are sufficient to scan a 4x4 matrix keypad, drive status LEDs, and switch relay or TRIAC outputs. The 1 KB EPROM holds the appliance state machine and timing tables, while the 25-byte RAM supports short counters and flags. The LP oscillator mode at 32.768 kHz keeps standby current low for line-powered appliances. Pin-compatible Flash replacements like PIC16F54-I/P ease firmware revisions.
Recommended
Industrial Timer and Counter Modules
The PIC16C56-LPI/P industrial-temperature grade and TMR0 8-bit timer/counter make it a fit for factory-floor timers, event counters, and process-interval controllers. The two-level hardware stack handles state transitions between IDLE/RUN/ALARM cleanly, while the 12-bit instruction width keeps cycle timing deterministic for control loops. At LP oscillator (32.768 kHz), a 1-second tick is achievable directly from TMR0 overflow with minimal software overhead. The 18-pin PDIP through-hole form factor also simplifies hand-rework on legacy equipment.
Recommended
Sensor Interface and Signal Conditioning
The PIC16C56-LPI/P suits low-cost sensor nodes where a microcontroller sequences excitation, reads a digital sensor, and drives an alarm output. The 12 I/O pins can be allocated to SPI-like bit-banged sensor reads, while TMR0 produces the timing reference. The 1 KB EPROM holds calibration tables and threshold logic for sensors like thermistors, Hall-effect switches, or simple optical interrupters. Industrial temperature rating allows deployment in non-climate-controlled cabinets.
Recommended
Consumer Electronics Remote Controls
The PIC16C56-LPI/P fits handheld remote controls where low power, low cost, and a small pin count dominate. The 12-bit instruction width produces compact IR protocol code that fits easily within the 1 KB EPROM. The LP oscillator mode minimizes battery drain during standby, while the 12 I/O pins accommodate a keypad matrix and IR LED driver. Through-hole PDIP allows simple hand-soldering for low-volume remote designs. The same-family PIC16C55-LP/P provides additional EPROM for more complex multi-protocol devices.
Recommended
LED Display Drivers and Chasers
The PIC16C56-LPI/P suits LED chasers, decorative lighting sequencers, and simple alphanumeric display drivers where the 12 I/O pins can multiplex 7-segment displays or drive Charlieplexed LED arrays. TMR0 produces the row-refresh interrupt base, while the 1 KB EPROM stores pattern tables. The 5 V supply aligns with LED forward voltages, and the industrial temperature rating supports outdoor or vehicle-interior use. The PDIP package is favored in hobbyist and small-batch lighting kits.
Recommended
Educational and Hobbyist Projects
The PIC16C56-LPI/P is a strong fit for educational microcontroller training kits and hobbyist projects because its 18-pin PDIP is breadboard-friendly and the simple PIC16C5X core avoids peripheral complexity. Students can practice assembly programming with the 12-bit RISC instruction set, build state machines for line-following robots, and implement PWM via TMR0. The 1 KB EPROM and 25-byte RAM impose useful constraints that teach resource-conscious coding. Drop-in same-family parts like PIC16C55-LP/P let projects scale memory without PCB changes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-LPI/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56-LPE/P | PIC16C56-LP/P | PIC16C56A-04E/P | PIC16C55-LP/P | PIC16F54-I/P |
|---|---|---|---|---|---|---|
| Package | PDIP-18 | PDIP-18 (same) | PDIP-18 (same) | PDIP-18 (same) | PDIP-18 (same) | PDIP-18 (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1 KB EPROM | 1 KB EPROM | 1 KB EPROM | 1 KB EPROM | 2 KB EPROM | 512 words Flash |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Memory Type | EPROM | EPROM | EPROM | EPROM | EPROM | Flash |
| Temperature Grade | Industrial -40C to +85C | Extended -40C to +125C | Commercial 0C to +70C | Extended -40C to +125C | Commercial 0C to +70C | Industrial -40C to +85C |
| Oscillator Mode | LP (low power) | LP (low power) | LP (low power) | XT (up to 4 MHz) | LP (low power) | XT/HS selectable |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | Active |
Key Differentiators
- Industrial temperature grade variant in same PDIP-18 footprint (vs PIC16C56-LP/P)
- Drop-in compatibility with extended-voltage family (vs PIC16C56-LPE/P)
- Drop-in migration path to Flash-based PIC16F54-I/P (vs PIC16F54-I/P)
- Same-family expansion to 2 KB EPROM via PIC16C55 (vs PIC16C55-LP/P)
Design Notes
The PIC16C56-LPI/P uses EPROM program memory and is NOT in-system programmable. Firmware must be fully validated in a windowed prototype before committing to masked silicon for production. Design in a Flash-based sibling such as PIC16F54-I/P if any firmware revision is likely after release, since EPROM one-time-programmable parts cannot be re-used after code lock.
The PIC16C5X core has a 2-level hardware stack, which limits nested subroutines to two calls deep. Deeply nested C-style code must be flattened or refactored into state-machine style code. Refer to Microchip PIC16C5X datasheet 30453D section on stack behavior, and consider PIC16F54-I/P (Flash, deeper stack via mid-range core) if your application requires deeper call nesting.
Place the LP oscillator crystal or resonator as close as possible to pins 15 (OSC2) and 16 (OSC1) with short, symmetrical traces. Add a ground guard ring around the oscillator traces to reduce EMI injection into adjacent signal lines. For 32.768 kHz operation, use a low-profile watch crystal with load capacitance matched to the on-chip oscillator load. Decoupling: 100 nF ceramic between VDD (pin 14) and VSS (pin 5) within 5 mm of the package.
At LP oscillator mode (32.768 kHz typical), the PIC16C56-LPI/P draws approximately 15 microamps active and a few microamps standby, making it well suited to battery or line-leakage-powered applications. For systems where the MCU is always powered, consider the PIC16C56A-04I/P XT variant which trades slightly higher current for faster wake and execution time. Validate brown-out behavior with a 100 nF bulk cap on VDD if the supply can dip below 3 V.
The PIC16C56-LPI/P has 12 bidirectional I/O pins (RA0-RA3, RB0-RB7). When used as outputs, each pin can source or sink up to 25 mA per pin and 100 mA total per port. For driving relays or LEDs directly, place a flyback diode across inductive loads and current-limit resistors on LEDs. For signal integrity, add 10 kohm pull-ups on MCLR (pin 4) to VDD through a 1 kohm series resistor to enable in-circuit programming headers during prototype bring-up.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified. NRND lifecycle status means long-term availability may be limited; consider PIC16F54-I/P for new designs.
