Question:
Please confirm whether there is any option to bit-reverse the loader file in the ADSP-214xx SPI slave boot mode?
Answer:
As SPI is a serial protocol which does not stipulate the order of the bits it can, and does, operate both ways. This is left to the hardware and firmware engineer to decide which way they choose to operate, as well as set timing and framing of words. One factor in making that decision, for example, is what peripherals they are talking to over SPI and what, if any, flexibility they have with respect to bit ordering.
The truth is the formatting of the loader stream for SPI boot is consistent with the PROM burner application we provide for use on our EZ-Kits. The choice of MSB/LSB first is a long-standing one that was driven by making examples that work "out-of-the-box" on our EZ-KIT.
We do, however, provide some 'hidden' Loader switches which may be useful, the -BitReverse and -NoBitReverse switches.
For VDSP:
We can add these to the 'Additional Options' in Project Options:Load
to control whether bit reversal is performed or not.
For CCES:
We can add these to the 'Additional Options' in Project properties > C/C++ Build > settings > Tool settings tab> CrossCore sharc loader > Additional Options.
We can also add the '-v' (verbose output) switch to the Loader command line to examine whether Bit Reversal is being performed on the Loader File or not.