PIC12F675 Unlock — What Is Actually Possible?
The PIC12F675 is an 8-pin, 8-bit Microchip microcontroller with 1024 words of flash program memory and 128 bytes of EEPROM data memory. When the code-protection (CP) configuration bit is programmed, standard ICSP reads return 0x0000 for every flash location. A PIC12F675 unlock bypasses this CP fuse to extract the original firmware — hex file and EEPROM contents — so you can maintain, repair, or re-program boards you own.
Our engineers routinely recover firmware from CP-protected PIC12F675 devices. Because this chip uses an older flash process (Microchip’s mid-range 14-bit core, 0.5 µm technology node), the protection is well-understood, and success rates exceed 90 % on samples in good physical condition. Turnaround is typically 3–5 working days from the moment we receive your chip.
How Does PIC12F675 Code Protection Work?
The PIC12F675 has a single CP bit in its configuration word at address 0x2007. When CP is cleared (value 0), the device blocks external read-out of flash addresses 0x0000–0x03FF via ICSP. EEPROM data (0x00–0x7F) is separately protected by the CPD bit. Both bits are set during production programming and survive power cycles.
Key technical details that affect a PIC12F675 unlock:
- Flash technology: Electrically-erasable flash, 14-bit instruction width, 1 K words.
- EEPROM: 128 bytes, independently protected by the CPD fuse.
- Supply voltage range: 2.0 V – 5.5 V (important for non-invasive parameter manipulation).
- Package: 8-pin PDIP / SOIC / DFN — easy to desolder and handle.
- No advanced security: No unique-ID authentication, no secure boot chain, no write-once OTP lock bits beyond CP/CPD.
Compared to newer Microchip parts with multi-level protection or secure-boot features, the PIC12F675’s single-fuse model is straightforward. This is why the chip is among the most feasible targets in our PIC12 family firmware recovery portfolio.
Our PIC12F675 Unlock Process — Step by Step
1. Feasibility Assessment (Free)
You submit the part number, package marking, and a brief description of why you need the firmware recovered. We verify the exact silicon revision — Microchip has shipped the PIC12F675 in at least three mask revisions (die revisions A through C), and each may respond slightly differently to extraction techniques. We confirm feasibility within one business day, at no cost.
2. Chip Intake and Inspection
We receive your physical chip (or the entire PCB if desoldering is risky). Under a stereo microscope we check for package damage, corrosion, re-marked parts, and confirm the die matches a genuine Microchip PIC12F675. Counterfeit or re-marked parts are flagged immediately — this happens roughly 5 % of the time with surplus-market chips.
3. Firmware Extraction
The specific technique depends on die revision and CP/CPD state. For PIC12F675 unlock, our lab uses a combination of:
- Voltage-glitch and timing-based non-invasive methods — exploiting the flash read timing window during ICSP entry sequences.
- Semi-invasive techniques — selective UV exposure or micro-probing after package decapsulation, when non-invasive paths are blocked by a newer die revision.
Non-invasive extraction preserves the chip for re-use. Semi-invasive work may consume the device — we always discuss this trade-off before proceeding.
4. Verification and Delivery
The extracted data is verified against a blank-chip read to confirm no bit errors. We deliver an Intel HEX file containing program flash (0x0000–0x03FF), configuration word, calibration constant (OSCCAL at 0x03FF), and EEPROM dump. You also receive a brief extraction report noting the method used and any caveats.
Cost and Turnaround for PIC12F675 Unlock
| Parameter | Typical Value | Notes |
|---|---|---|
| Feasibility check | Free | 1 business day |
| Standard extraction | $150 – $350 | Non-invasive preferred; price depends on CP+CPD state and die revision |
| Semi-invasive extraction | $300 – $500 | Required for certain revisions; chip may not survive |
| Turnaround (standard) | 3 – 5 working days | From chip receipt to HEX delivery |
| Rush service | +40 % surcharge | 1 – 2 working days |
| Deliverables | Intel HEX + EEPROM + OSCCAL | Includes extraction report |
Pricing is per unique firmware image. If you have a batch of identical boards, one extraction covers all of them — you simply re-program additional blank PIC12F675 chips with the recovered HEX. Bulk re-programming support is available on request.
Why the OSCCAL Value Matters
The PIC12F675 stores a factory-calibrated oscillator constant (OSCCAL) at the last flash address (0x03FF). If this value is lost during a bulk erase or a failed programming attempt, the internal 4 MHz RC oscillator drifts by as much as ±10 %, which can break UART timing, sensor sampling, and sleep-mode wake-up intervals.
During every PIC12F675 unlock we capture the OSCCAL value and include it in the HEX file. If you’ve already erased the chip and lost OSCCAL, we can characterize the oscillator on your specific die and derive a replacement calibration byte — this is a common recovery scenario we handle alongside firmware extraction.
When PIC12F675 Unlock Is — and Isn’t — the Right Path
Good candidates
- Legacy boards where the original design house is defunct and you hold IP rights.
- Field equipment running PIC12F675 firmware you developed but lost the source for.
- Prototype recovery where the only copy of working firmware sits inside a CP-locked sample.
Poor candidates or red flags
- Third-party proprietary products where you have no ownership or license — we require proof of authorization before starting work. See our IC extraction service policy for details.
- Chips with physical damage (cracked die, corroded bond wires) — success drops below 50 %.
- Re-marked or counterfeit parts — if the die isn’t a genuine Microchip PIC12F675, extraction parameters won’t match and the attempt will fail.
PIC12F675 vs. Related Microchip Parts
| Feature | PIC12F675 | PIC12F508 | PIC16F887 | PIC18F2550 |
|---|---|---|---|---|
| Core | Mid-range 14-bit | Baseline 12-bit | Mid-range 14-bit | High-perf 16-bit |
| Flash size | 1 K words | 512 words (OTP-like) | 8 K words | 16 K words |
| Protection model | CP + CPD fuses | CP fuse only | CP0–CP3 block fuses | CP + CPB + CPD + WRT |
| Unlock difficulty | Low–moderate | Low | Moderate | Moderate–high |
| Typical turnaround | 3–5 days | 2–4 days | 5–7 days | 5–10 days |
If your project involves multiple Microchip devices, we handle the full range — from the PIC12F508 with its simpler OTP-style flash up through PIC18F2550 code-protection recovery. Cross-family work (e.g., migrating from PIC to STM32) is also supported through our broader MCU unlock service.
Authorization and Legal Requirements
Every PIC12F675 unlock engagement requires documented proof of ownership or written authorization from the IP holder. We operate under NDA by default. Common acceptable documentation includes purchase invoices, design files, company letterhead authorization, or a sworn declaration of IP ownership. This protects both parties and ensures compliance with trade-secret and IP law in your jurisdiction.
Frequently Asked Questions
Can the PIC12F675 be re-used after firmware extraction?
If we use a non-invasive method — which is the default for most PIC12F675 die revisions — the chip survives and can be re-programmed. Semi-invasive decapsulation destroys the package, so the die cannot be soldered back. We always confirm which path applies before we begin.
What if my PIC12F675 has been bulk-erased and I only need OSCCAL?
We can characterize the internal oscillator on your specific die and provide a replacement OSCCAL byte. This is a separate, lower-cost service (typically $50–$80) and takes 1–2 working days.
Do you support PIC12F675 variants like the PIC12F675T-I/SN?
Yes. All packaging variants (PDIP, SOIC, DFN) and temperature grades (-I, -E) share the same die. The extraction process is identical; only desoldering and handling differ.
How does PIC12F675 protection compare to STM32 read-out protection?
The PIC12F675 uses a simple one-bit fuse model with no escalation levels. STM32 devices use multi-level RDP (Level 0/1/2), where Level 2 is often permanently locked. A PIC16 family unlock or PIC12F675 job is significantly more straightforward than an STM32 RDP-2 attempt.
Can you extract firmware remotely without receiving the physical chip?
No. Code-protection bypass requires physical access to the device. You ship the chip (or entire PCB) to our lab. We provide a prepaid return label for the recovered chip and deliver the HEX file electronically.
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