PIC16C56-HSE/SS - 8-Bit 16MHz OTP MCU 1.5KB | Microchip
MPN: PIC16C56-HSE/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.85 | $38.50 |
| 100 | $3.42 | $342.00 |
| 500 | $3.05 | $1,525.00 |
| 1,000 | $2.72 | $2,720.00 |
| 3,000 | $2.45 | $7,350.00 |
PIC16C56-HSE/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data bus and a Harvard architecture, integrating a CPU, program memory, working RAM, and basic peripherals. PIC microcontrollers sit in the broader hierarchy: 8-bit MCU -> microcontroller -> embedded controller -> semiconductor IC. They are commonly used in cost-sensitive embedded designs where deterministic instruction execution and a small footprint are more important than raw compute throughput.
Key features of the PIC16C56 include 12-bit-wide instructions for 2:1 code compression over competitive 8-bit cores, a fully static design that allows clock stopping, on-chip Power-On Reset (POR), a Watchdog Timer (WDT) for code-flow recovery, and 12 dedicated I/O pins arranged across ports A and B. Its 20-bit instruction word with 12-bit opcode keeps firmware compact for the 1K-word program-memory address space.
The device uses a RISC-style instruction set of 33 single-word/single-cycle instructions, executing most instructions in a single 4-clock instruction cycle (200ns at 20MHz max). The architecture supports interrupt-driven designs with optional peripheral features selectable at programming time. Industrial- and consumer-grade temperature grades are available, and the OTP cell is field-programmable using standard EPROM programmers.
Typical applications include low-cost consumer appliances, remote-control transmitters, sensor-interface front ends, LED display controllers, battery-powered timing circuits, and simple industrial control loops. Because the part is OTP rather than flash, it is best suited for mature, high-volume products where firmware is finalized and field re-programming is not required.
When designing with the PIC16C56-HSE/SS, ensure a clean +5V (or 3V) rail with a 0.1uF decoupling capacitor near VDD, and route the 16MHz crystal with short, symmetric traces. Because the device is OTP, the firmware image must be fully validated before programming; consider PIC16F56 (flash-based) for prototypes.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives, and practical design notes that go beyond the manufacturer datasheet. The accompanying FAQ and comparison tables are optimized for engineers searching for a drop-in PIC16C56 replacement or evaluating migration to flash-based PIC16F56.
Drop-in alternatives for PIC16C56-HSE/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-HSE/SS (same form factor and footprint) — differing in Package, Core Architecture, Program Memory Size, Maximum Clock Frequency, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F56-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F57-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56A-20I/SS
✅ Drop-In✓ In Stock
$0.67 / Unit
View Datasheet →PIC16C56-HS/SS
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C56AT-20E/SS
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56-HSE/SS Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC16C5X RISC |
| Architecture | Harvard, 12-bit instruction word |
| Program Memory | 1.5KB (1K x 12) OTP EPROM |
| Data RAM | 25 bytes |
| Data EEPROM | None (ROM-less for data) |
| Maximum Clock Frequency | 16 MHz |
| Instruction Cycle Time | 250 ns at 16 MHz (4-clock cycle) |
| Instruction Set Size | 33 single-word instructions |
| Supply Voltage (VDD) | 3.0 V to 5.5 V |
| I/O Pins | 12 (PORTA 4-bit + PORTB 8-bit, multiplexed) |
| Timers | 1 x 8-bit RTCC (Timer0) |
| Watchdog Timer (WDT) | Yes, on-chip |
| Power-On Reset (POR) | Yes |
| Oscillator Mode (HSE) | High-speed crystal/resonator (XT/HS range) |
| ADC | None (no on-chip ADC) |
| UART/USART | None |
| I2C/SPI | None (bit-bang only) |
| Interrupts | External RB0/INT + peripheral |
| Operating Temperature Range | 0C to +70C (commercial, per HSE/SS) |
| Package | 20-SSOP (SS) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life, hermetic OTP package) |
| Programming Method | One-Time Programmable (OTP) via EPROM programmer |
| Programmer Compatibility | MPLAB PM3, PICSTART Plus, PRO MATE II |
PIC16C56-HSE/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O, PORTA bit 2 |
| Pin 2 | RA3 — Bidirectional I/O, PORTA bit 3 |
| Pin 3 | T0CKI — Timer0 clock input (alternate RA4 function) |
| Pin 4 | MCLR/VPP — Master clear reset / programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 7 | RB1 — Bidirectional I/O, PORTB bit 1 |
| Pin 8 | RB2 — Bidirectional I/O, PORTB bit 2 |
| Pin 9 | RB3 — Bidirectional I/O, PORTB bit 3 |
| Pin 10 | RB4 — Bidirectional I/O, PORTB bit 4 |
| Pin 11 | RB5 — Bidirectional I/O, PORTB bit 5 |
| Pin 12 | RB6 — Bidirectional I/O, PORTB bit 6 / serial programming clock |
| Pin 13 | RB7 — Bidirectional I/O, PORTB bit 7 / serial programming data |
| Pin 14 | VDD — Positive supply voltage (+3.0V to +5.5V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output (Fosc/4) |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input (HSE mode for 16MHz crystal) |
| Pin 17 | RA0 — Bidirectional I/O, PORTA bit 0 |
| Pin 18 | RA1 — Bidirectional I/O, PORTA bit 1 |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C56-HSE/SS is suitable for 7 applications: Remote Control Transmitters, Consumer Appliance Control Boards, LED Display Drivers and Chasers, Sensor Interface Front Ends, Battery-Powered Timing Circuits, Industrial Control Loops, Toys and Hobby Electronics.
Remote Control Transmitters
The PIC16C56-HSE/SS is well-suited for infrared or RF remote-control transmitters where 1.5KB of OTP memory holds fixed button-mapping firmware and the 16MHz clock drives precise carrier-frequency generation. The 12 GPIO pins are sufficient to scan a 4x4 keypad matrix, and the 25-byte RAM accommodates button debounce state and LED indicators. At 16MHz the instruction cycle is 250ns, providing deterministic timing for IR protocols such as RC5 or NEC. The OTP cell locks in the OEM's button layout, preventing firmware cloning. Compared to a flash-based PIC16F56, the OTP variant reduces per-unit cost in high-volume consumer remotes.
Recommended
Consumer Appliance Control Boards
The PIC16C56-HSE/SS works in white-goods controllers such as microwave ovens, rice cookers, and washing-machine user-interface panels, where its 12 I/O pins drive 7-segment LED displays and read membrane keypads. The on-chip WDT (Watchdog Timer) recovers from firmware lockups caused by EMI, while Power-On Reset ensures clean startup after power interruptions. The 3.0V to 5.5V VDD range tolerates the voltage sags typical of relay-driven appliance power rails. Because appliance firmware is frozen at production time, OTP memory is the cost-optimized choice over flash in this application space.
Recommended
LED Display Drivers and Chasers
The PIC16C56-HSE/SS drives LED chaser and decorative-lighting controllers by bit-banging up to 12 LED outputs while the 16MHz clock provides smooth PWM-free chase patterns. The 8-bit RTCC timer generates precise timing bases for blink rates, and the OTP cell locks in unique lighting sequences per SKU. With only 25 bytes of RAM, the firmware uses a compact state machine rather than lookup tables. The 20-SSOP package is small enough to fit inside decorative light strings. For designs needing in-field firmware updates, swap to the PIC16F56-I/SS in the same footprint.
Recommended
Sensor Interface Front Ends
The PIC16C56-HSE/SS reads low-speed digital sensors (Hall-effect switches, reed contacts, thermistor bridges conditioned externally) and outputs a serial bit stream via bit-banged GPIO. The 12 I/O pins support multiple sensor inputs plus a status LED, and the WDT recovers from sensor glitches. Because no on-chip ADC exists, all sensor signal conditioning is done externally with op-amps or comparators. The 16MHz instruction cycle drives sub-microsecond pulse timing for ultrasonic or capacitive sensing front ends.
Recommended
Battery-Powered Timing Circuits
The PIC16C56-HSE/SS operates in battery-powered timer applications such as garden-watering controllers, kitchen timers, and electronic thermostats. The fully static core allows the clock to be stopped in sleep mode (current drops to a few microamps per Microchip datasheet 30453D), then restarted via Watchdog Timer wake-up. The 3.0V minimum VDD is compatible with two fresh AA cells. The 25-byte RAM is sufficient to hold elapsed-time counters and schedule flags. The 16MHz HSE mode can be replaced with the internal 32kHz LP oscillator for ultra-low-power applications.
Recommended
Industrial Control Loops
The PIC16C56-HSE/SS implements simple industrial timing and sequencing functions, such as conveyor-segment controllers, valve pulse timers, and machine-status indicators. The 12 I/O pins drive optocouplers to isolated 24V loads, and the WDT provides fault recovery if firmware execution is corrupted by EMI. The commercial 0C to +70C temperature range is suitable for indoor industrial panels. For harsh environments, upgrade to the PIC16C56A-20I/SS (-40C to +85C industrial grade) or migrate to the active PIC16F57-I/SS for supply-chain resilience.
Recommended
Toys and Hobby Electronics
The PIC16C56-HSE/SS drives sound effects, motor sequences, and LED patterns in mass-market electronic toys. The 1.5KB OTP memory holds fixed audio-sample playback code and motor-control state machines, while the 16MHz instruction cycle generates PWM-like waveforms by software. The 20-SSOP package is small enough for handheld toys, and the OTP cell prevents firmware cloning by competitors. At high production volumes the OTP cell is more cost-effective than flash, and the PIC16C56-HSE/SS is widely second-sourced through multiple Microchip distributor channels.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-HSE/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F56-I/SS | PIC16F57-I/SS | PIC16C56A-20I/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Program Memory Type | OTP EPROM (1.5KB) | Flash (1.5KB) | Flash (3KB) | OTP EPROM (1.5KB) | Flash (768B) |
| Max Clock Frequency | 16 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Data RAM | 25 bytes | 25 bytes | 72 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 20 | 12 | 12 |
| ADC | None | None | None | None | None |
| Lifecycle Status | Obsolete | Active | Active | Obsolete | Active |
| Operating Temperature | 0C to +70C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Approx Unit Price (qty 1, USD) | $4.20 | $1.95 | $2.10 | $4.50 | $1.65 |
Key Differentiators
- Flash memory for in-circuit reprogramming and field updates (vs PIC16C56-HSE/SS)
- Larger 3KB flash and 72-byte RAM for more complex firmware (vs PIC16F56-I/SS)
- 20 MHz max clock for higher-throughput timing applications (vs PIC16C56-HSE/SS)
- Industrial -40C to +85C temperature range vs commercial 0C to +70C (vs PIC16C56A-20I/SS)
- Active production status with shorter lead times (vs PIC16C56-HSE/SS)
Design Notes
Place a 0.1uF ceramic decoupling capacitor as close as possible between VDD (pin 14) and VSS (pin 5) of the PIC16C56-HSE/SS. For designs with multiple ICs, add a bulk 10uF tantalum or aluminum electrolytic capacitor on the main +5V rail. The PIC16C5X core draws typically 2-5 mA active at 16MHz, rising to 15 mA with all GPIO loaded. Place the bulk cap within 1 inch of the MCU. Inductive loads on GPIO should be diode-clamped to VDD to prevent latch-up during power transients.
Route the 16MHz HSE crystal traces (OSC1 pin 16 and OSC2 pin 15) as short as possible, ideally under 5mm, and symmetric to avoid duty-cycle distortion. Place load capacitors (typically 15-33pF, value per crystal datasheet) within 2mm of OSC1/OSC2. Keep crystal traces away from switching signals and noisy power traces. Use a ground pour under the crystal area to provide a stable reference plane. The MCLR/VPP pin (pin 4) requires a 10kohm pull-up to VDD for normal operation; during programming it is driven to 13V.
The PIC16C56-HSE/SS is One-Time Programmable - once programmed it cannot be erased or rewritten. Always validate firmware on a flash-based PIC16F56 development board before committing to the OTP version. The HSE suffix indicates a 16MHz high-speed external oscillator; do not substitute an HS-only crystal without recalculating instruction-cycle timing. The 25-byte RAM limit means large lookup tables must be implemented as computed values or stored in program memory (via retlw instructions), not in RAM. Per Microchip datasheet 30453D, the Watchdog Timer is enabled by configuration fuse, not by software.
The 20-SSOP package has a 0.65mm pin pitch requiring careful PCB layout. Use 0.4mm-wide traces exiting the SSOP pads, fanning out to via-in-pad or near-pad vias for inner-layer routing. Maintain 0.2mm clearance between adjacent SSOP pins. The exposed thermal pad (if present on this package variant) should be soldered to a copper pour for mechanical stability, though the PIC16C56 has low thermal dissipation and does not strictly require the pad for thermal relief. Per Microchip SSOP land-pattern recommendations, the pads should be 0.45mm wide x 1.9mm long.
Estimated: The PIC16C56-HSE/SS dissipates approximately 75 mW at 16MHz with 5V VDD and typical I/O loading (assuming 2-5 mA active current per Microchip datasheet 30453D). At a theta_JA of approximately 90 C/W for the 20-SSOP package, the junction temperature rises about 7C above ambient, well within the 0C to +70C commercial operating range. For industrial environments near 85C ambient, junction temperature stays around 92C, well below the 150C maximum. No heatsink is required.
Compliance Information
Compliance status for PIC16C56-HSE/SS could not be verified from available web data. The PIC16C5X OTP family was originally released in the 1990s, prior to mandatory RoHS compliance. AEC-Q100 is not applicable as this is a general-purpose commercial-grade MCU, not an automotive-qualified part. For automotive applications, use PIC16F56-I/SS with external qualification.
