The PIC16F1934 stretches the 193x LCD family across a 40/44-pin body: thirty-six I/O lines, a fourteen-channel 10-bit ADC, sixteen capacitive-touch channels, and an LCD driver covering twenty-four segments over four commons – ninety-six pixels – while program flash stays at 4096 words (7 KB) with 256 bytes of SRAM and 256 bytes of EEPROM. The ratio is the design point: a large glass with deliberately light code, typical of instruments where the display is the product. Our clone protected PIC16F1934 MCU service recovers the whole image from hardware you own when its protection is engaged.

Cloning a display-first product

Ninety-six segments give a product a real user interface, and the firmware’s display work is constant-driven: mux configuration, bias control, frame timing, and the font map that turns values into glyphs. A byte-perfect clone with a mis-captured font map fails the way displays do – quietly, one annunciator at a time. Verification therefore runs both units through a scripted state sequence and compares every segment; the comparison record travels with the image. Because the code space is small, capture discipline matters proportionally more: a single mis-read sector can be a visible fraction of the array. The array is read in one protected-state pass, checksummed per sector, and re-read until two passes agree. The 14-bit word addressing that shapes the heximal is explained in the microcontroller firmware instruction reference.

Glass vendors matter more on ninety-six segments than on smaller panels. Two suppliers of the same nominal glass bias slightly differently, and the firmware’s contrast and bias constants were chosen for the supplier the product actually shipped with. Where a customer’s fleet mixes glasses, the diff between the two constant sets is small but decisive, and the report names which image suits which panel. It is the kind of detail that never reaches a datasheet and always reaches a returns desk.

Where the seven kilobytes go

Display-first firmware spends its flash on tables – fonts, messages, calibration curves – and its SRAM on frame buffers and accumulation registers. That makes the 256 bytes of SRAM and 256 bytes of EEPROM the scarce resources, and the EEPROM usually holds the counters and service flags a maintenance team actually needs. Both arrays are captured together; the report keeps the EEPROM beside the code with its checksum, because a clone that resets the user’s accumulated totals is a clone that gets rejected on sight. Lawful-access framing is in the unlock microcontroller embedded memory guide.

Frame-buffer budgeting is the other small-die discipline: with 256 bytes of SRAM, the display code keeps its working set tight, and constants that decide how much of the frame is buffered where are part of the image’s behaviour. Our register-state dump captures the LCD registers in their powered state so those decisions are visible, and the report marks them as verified rather than inferred, and flags any register whose value the startup code rewrites before the first frame.

Where the working set overflows, the symptoms appear as flicker under load rather than as a fault code, which is why the comparison runs the display at full update rate.

Protection and handling

Code protect and data protect live in the configuration words, refuse external reads when set, and clear only through the bulk erase that destroys the array – so the erase is permanently out of the plan. The capture maps the configuration words, reads what answers, and records the policy verbatim. Physically, the 40/44-pin TQFP and PDIP donors are gentle to fixture, but thermal history still shows: lead inspection precedes every fine-pitch capture, and sessions are kept short so a marginal contact costs minutes. The 28-pin entry member of the family is on the PIC16F1933 memory page for comparison.

Duplication and scope

Verified images are programmed into matching 40/44-pin blanks with configuration words and EEPROM restored, through the MCU flash EEPROM data cloning pipeline with per-unit read-back; the 14 KB 40/44-pin member is on the PIC16F1937 EEPROM recovery and the analogue flagship 171x line on the PIC16F1719 flash page.

Only units you own or are authorised to service are accepted. Send the locked PIC16F1934 and the return is a verified image with the segment-by-segment proof and the protection map attached.