PIC16C56-RC/SS - 8-bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC16C56-RC/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.06 | $4.06 |
| 10 | $3.82 | $38.20 |
| 100 | $3.45 | $345.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.7 | $2,700.00 |
PIC16C56-RC/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, program memory (ROM/EPROM/Flash), data memory (RAM), and peripheral set on one die. Within the broader taxonomy, an MCU sits under microprocessor -> microcontroller -> embedded controller -> semiconductor. PIC microcontrollers are RISC-based devices known for a small instruction set, low power, and deterministic interrupt response; the PIC16C5X sub-family uses a 12-bit-wide instruction word and a 2-level hardware stack, making it one of the most resource-constrained but lowest-cost Microchip offerings.
Key features include 12 I/O pins, a single 8-bit timer/counter (TMR0) with a prescaler, 33 single-word single-cycle instructions, direct/indirect/relative addressing modes, and a watchdog timer for unattended operation. The 'RC' suffix denotes the resonator/RC oscillator clock option, which lets the design use an external RC network or ceramic resonator instead of a crystal, reducing BOM cost. The /SS suffix indicates the 20-pin SSOP industrial/commercial temperature grade package.
The PIC16C56 implements a Harvard architecture with separate program and data buses, a 2-level deep hardware call stack, and 7-8 special function hardware registers. Program memory is OTP, meaning it is written once and not erasable, which favors mature production designs where firmware is finalized and unit cost dominates over reprogrammability.
Typical applications include low-cost consumer appliances, sensor signal conditioning front-ends, simple motor controllers, remote-control transmitters, and battery-powered metering devices where the 4 MHz instruction rate and small pin count are sufficient.
Design with OTP memory in mind: once programmed, the device cannot be erased. Plan firmware revisions using a Flash-based PIC16F5X cousin during development, then port to PIC16C56 for production cost reduction.
This page synthesizes distributor pricing, verified drop-in alternatives from the PIC16C5X family, and practical design notes that go beyond the manufacturer datasheet's parameter tables.
Drop-in alternatives for PIC16C56-RC/SS — 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-RC/SS (same form factor and footprint) — differing in Core Architecture, Package, Timers, Mounting Type, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56-HSI/SS
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16C56AT-20/SS
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC16C56A-20I/SS
✅ Drop-In✓ In Stock
$0.67 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56-RC/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM Size | 25 bytes |
| Instruction Word Width | 12-bit |
| Maximum CPU Frequency | 4 MHz |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) |
| Hardware Stack Depth | 2 levels |
| Instruction Set Size | 33 instructions |
| Addressing Modes | Direct, Indirect, Relative |
| Supply Voltage | 3.3 V / 5 V |
| Oscillator Option | External RC or ceramic resonator (RC suffix) |
| Watchdog Timer | Yes |
| Package | 20-SSOP (5.30 mm body) |
| Mounting Type | Surface Mount (gull-wing) |
PIC16C56-RC/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O port B bit 0 / external interrupt input |
| Pin 7 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 |
| Pin 14 | VDD — Positive supply voltage (3.3V / 5V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output (Fosc/4) |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C56-RC/SS is suitable for 6 applications: Low-Cost Consumer Appliance Controller, Remote-Control Transmitter / Receiver, Sensor Signal Conditioning Front-End, Battery-Powered Metering Device, Simple Stepper / DC Motor Sub-Controller, LED Display / Sign Controller.
Low-Cost Consumer Appliance Controller
The PIC16C56-RC/SS fits low-cost consumer appliances (toasters, coffee makers, rice cookers, simple washing-machine sub-boards) where the MCU drives relays, reads buttons, and drives 7-segment or LED indicators. Its 12 I/O pins are sufficient for key-scan input, segment/relay output, and a buzzer. The 1.5 KB OTP memory holds a fixed-function control loop; the 4 MHz instruction rate handles button debounce and timing with margin. Unlike the Flash-based PIC16F54-I/SS, the OTP variant is one-time programmable, lowering per-unit BOM cost in high-volume mature SKUs. The RC oscillator option lets the design skip the crystal, reducing the BOM by ~$0.10 per unit.
Recommended
Remote-Control Transmitter / Receiver
The PIC16C56-RC/SS serves as the encoder/decoder in low-cost IR or RF remote-control systems for toys, ceiling fans, garage-door openers, and simple appliance remotes. Its 8-bit TMR0 with prescaler generates precise carrier-frequency timing (e.g., 38 kHz for IR modulation), and the 12 I/O pins handle button matrix scanning, status LEDs, and the IR/RF output transistor. The 33-instruction PIC16C5X ISA is small enough to fit single-byte pulse-width encoders into 1.5 KB. Power consumption is low thanks to the CMOS process, suiting battery-powered transmitters. The RC oscillator option saves a crystal and lowers standby current vs an XT crystal in idle.
Recommended
Sensor Signal Conditioning Front-End
In sensor front-ends (thermistor bridges, simple photodiode amplifiers, reed-switch debouncers), the PIC16C56-RC/SS reads analog signals via a discrete RC ADC or external sigma-delta modulator, applies calibration constants stored in OTP, and outputs a clean UART or PWM telemetry stream. Its 8-bit ALU is adequate for linearization and moving-average filtering of slow sensor signals (temperature, humidity, pressure). The 25-byte RAM holds a small sample buffer, and the 1.5 KB program memory fits the calibration lookup tables. Industrial sensor modules that have been in production for years often lock firmware into OTP to prevent field tampering, making PIC16C56 a cost-effective fit.
Recommended
Battery-Powered Metering Device
Battery-powered metering devices (water meters, gas meters, simple kWh monitors) leverage the PIC16C56-RC/SS CMOS low-power design and 25-byte RAM to log consumption pulses, drive an LCD or mechanical-register stepper, and sleep between events. TMR0's watchdog wakes the device periodically, counts pulses from a reed switch or Hall sensor, accumulates in RAM, and returns to sleep. The 4 MHz instruction rate gives ample headroom for pulse-counting and debounce. The OTP memory locks the calibration and tariff schedule, which is a regulatory requirement in many metering jurisdictions. The SSOP-20 package allows compact PCB integration inside meter enclosures.
Recommended
Simple Stepper / DC Motor Sub-Controller
As a sub-controller in multi-MCU systems, the PIC16C56-RC/SS handles low-level stepper or brushed-DC motor commutation, PWM generation via software bit-banging on I/O pins, and end-stop / overcurrent feedback. Its deterministic 4 MHz instruction cycle (1 us/instruction) gives predictable step timing for low-RPM stepper motors (e.g., valve actuators, small syringe pumps). The 12 I/O pins drive two H-bridges' direction/enable lines plus home-switch inputs. Program memory fits step tables for half-step and full-step microstepping. The SSOP-20 package is small enough to mount on the motor-PCB next to the H-bridge drivers.
Recommended
LED Display / Sign Controller
The PIC16C56-RC/SS drives small LED matrix displays (8x8 single-color, 7-segment multi-digit) in scrolling-sign, scoreboard, and price-tag applications. Software-driven Charlieplexing or matrix multiplexing on 12 I/O pins can drive up to 16 LEDs in Charlieplex or 8x8 single-color at modest refresh rates. The 4 MHz core supports refresh rates above 100 Hz to avoid flicker. 1.5 KB OTP holds font tables and animation sequences for fixed-content signs. The SSOP-20 package fits compact PCB designs behind LED panels, and the RC oscillator option removes the crystal cost in cost-sensitive retail signage.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-RC/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56-HSI/SS | PIC16C56AT-20/SS | PIC16C56A-20I/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|
| Package | 20-SSOP (5.30 mm) | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Core / Family | PIC16C5X (8-bit RISC) | PIC16C5X (8-bit RISC) - same | PIC16C5X (8-bit RISC, 'A' silicon rev) | PIC16C5X (8-bit RISC, 'A' silicon rev) | PIC16F5X (8-bit RISC, Flash) |
| Program Memory Type | OTP EPROM (1.5 KB) | OTP EPROM (1.5 KB) | OTP EPROM (1.5 KB) | OTP EPROM (1.5 KB) | Flash (1.5 KB) - reprogrammable |
| Max CPU Frequency | 4 MHz (RC osc option) | 20 MHz (HS osc option) | 20 MHz (XT/HS) | 20 MHz (XT/HS) | 20 MHz |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 |
| Lifecycle | Obsolete (PIC16C5X OTP EOL) | Obsolete (PIC16C5X OTP EOL) | Obsolete (PIC16C5X OTP EOL) | Obsolete (PIC16C5X OTP EOL) | Active (Flash successor) |
Key Differentiators
- Lowest-cost OTP option in PIC16C5X family with RC oscillator (vs PIC16C56-HSI/SS)
- Obsolete / end-of-life, replaced by Flash-based PIC16F54-I/SS (vs PIC16F54-I/SS)
- Maximum 4 MHz CPU clock (RC oscillator option) (vs PIC16C56AT-20/SS)
Design Notes
The PIC16C56 is OTP (One-Time-Programmable) and cannot be re-programmed or erased. Plan firmware revision cycles using the Flash-based PIC16F54-I/SS as a development surrogate, then port the locked firmware to PIC16C56-RC/SS for production cost reduction. Once a PIC16C56 is programmed with a bug, the part is bricked - budget for programming yield loss (typically 1-3%) in production cost calculations.
Place the MCLR pull-up resistor (typically 10 kohm) within 5 mm of pin 4 to ensure reliable reset during power-up and brown-out. The MCLR pin is the only reset source on PIC16C5X (no internal BOR or software reset beyond watchdog). Add a 100 nF decoupling capacitor between VDD (pin 14) and VSS (pin 5), routed as close to the IC as possible with a short, wide trace to minimize supply noise during I/O switching transients.
The 'RC' oscillator option requires an external resistor and capacitor on OSC1 (pin 16) with OSC2 (pin 15) left open or driving a low-impedance buffer. RC timing accuracy is typically ±5% to ±10% across temperature, sufficient for non-timing-critical applications like relay control or LED multiplexing but NOT for UART baud-rate generation. If your firmware uses serial comms, switch to PIC16C56-HSI/SS with a crystal oscillator or migrate to PIC16F54-I/SS for stable clock and reprogrammability.
Compliance Information
RoHS, lead-free, and halogen-free status for PIC16C56-RC/SS were not present in the verified web data and require confirmation against the manufacturer datasheet. AEC-Q100 is not applicable (8-bit MCU, no automotive qualification in this OTP family). All Microchip products comply with Section 1502 of the Dodd-Frank Act regarding conflict minerals per the company policy.
