13 · Keep a design after power-off

Every other example loads a .sof: it runs until the power goes off. The MAX 10 also has its own configuration flash: write a design there and the board starts it by itself at every power-up.

Flashed and verified on the board 2026-10-24 Power-cycle check: to do by hand Skill: flash-design

Its project: gamepad.qar (example 04)

.sof or .pof

	.sof (SRAM Object File)	.pof (Programmer Object File)
Goes into	the FPGA's configuration memory (SRAM)	the MAX 10's internal flash (CFM, plus UFM)
Lasts	until power-off	until something else is flashed; loads itself at every power-up
Takes	about 2 s	about 15 s (write + verify)
Use for	every build while developing	the finished design: a demo, a product, a classroom board

Every build in this BKM already makes both: output_files/<name>.sof and <name>.pof (the projects use INTERNAL_FLASH_UPDATE_MODE "SINGLE IMAGE WITH ERAM", so ROM and RAM contents are in the flash image too).

Do it

python scripts/de10.py flash examples/04_gamepad       # writes and verifies the flash
→ Info: Quartus Prime Programmer was successful. 0 errors, 0 warnings
→ OK: flashed and verified; it starts at the next power-up

Under the hood: quartus_pgm -m jtag -o "pv;output_files/gamepad.pof" (p = program, v = verify). Or in the Quartus Programmer: add the .pof, tick Program/Configure and Verify on the CFM and UFM rows, Start.

Measured on the board

The game-pad tester (example 04) was flashed and verified without errors.
Right after programming, the MAX 10 reloaded itself from the new flash image: the board answered over USB with example 04's status line, its frame counter showing it had just started.
Still to do by hand: unplug the USB cable, plug it back, and see the game-pad screen come up without the PC doing anything. (This replaces whatever the board started with before; the original streaks demo is gone.)

Good to know

Loading a .sof afterwards does not touch the flash: develop as usual, and the flashed design comes back at the next power-up.
The MAX 10 can also hold two images and choose at power-up (the dual-image mode, selected by the CONFIG_SEL pin, or switched from your design with the Dual Configuration IP). Not built here.
The UFM (user flash memory) part of the flash can hold your own data that survives power-off, through the On-Chip Flash IP. Not built here.