Flashing CW312T-K82F on a ChipWhisperer-Husky - recommended workflow? (spsdk ISP vs J-Link)

Flashing CW312T-K82F on a ChipWhisperer-Husky — recommended workflow? (spsdk ISP vs J-Link)

Setup

  • ChipWhisperer-Husky, CW312T-K82F target in the Husky’s CW313 socket

  • Windows 11, ChipWhisperer 5.7.0, ARM GNU toolchain 13.2

What already works

I built simpleserial-aes for PLATFORM=CW308_K82F (CRYPTO_TARGET=TINYAES128C) with no issues — it produces simpleserial-aes-CW308_K82F.hex/.bin. The capture side is fully functional: the target answers SimpleSerial, and a captured AES-128 matches the FIPS-197 vector exactly:


key 2b7e151628aed2a6abf7158809cf4f3c

pt 6bc1bee22e409f96e93d7e117393172a

ct 3ad77bb40d7a3660a89ecaf32466ef97 (matches)

So scope, clock (7.37 MHz on HS2), reset and serial all behave.

The problem: flashing my own build

cw.programmers in 5.7.0 only exposes SAM4S / STM32F / AVR / XMEGA / iCE40 / NEORV32 — there is no Kinetis/K82F programmer, so cw.program_target(...) can’t flash this board. I understand from other threads that the CW-Lite/Husky MPSSE→OpenOCD path is not supported for the K82F, so I don’t want to chase that.

I’d like to use the spsdk/blhost ISP route (the “pull PTA4 low via R5, enter ROM bootloader” method). A few questions before I poke at the hardware:

  1. Serial port — can I use the Husky’s own USB-CDC serial (the COM port the target UART is bridged to) as the blhost UART, or do I need a separate USB-UART adapter wired to the target RX/TX/GND? Does the K82F ROM bootloader’s LPUART0 land on the same pins the CW serial is wired to?

  2. R5 / PTA4 — can you confirm that on the CW312T-K82F, R5 is the PTA4/NMI pull-up and that grounding its low (MCU-side) pad is the correct way to force ISP mode? I had trouble locating it physically.

  3. Jumpers — is there a recommended CW313 jumper configuration specifically for ISP-mode flashing (as opposed to the JTAG / J-VREF=3.3V config you’ve mentioned for J-Link)?

  4. J-Link — for Windows, is a Segger J-Link on the CW313 JTAG header (J5/HDR6, J-VREF→3.3V) still the most reliable route overall?

Thanks!

We haven’t tested programming on this target via UART, but theoretically you should be okay going through the Husky’s CDC port. If you run into issues and have a USB/UART cable handy, that might be a good thing to change out first though. LPUART0 lands on the same pins the serial is used for.

I don’t think we’ve tested anything besides J-Link programming on this target, so I can’t give recommendations for anything besides that.