I am debugging the booting of a DM6437 DSP via the 24-bit address SPI Master boot mode. In looking at the processor activity on the SPI bus after power up, I see a read of address 0 (fetching the value 3, which indicates a 24-bit address SPI part), and then see fetches of address 4, 5, 6, 7 (to get the 'magic' word of 0x41504954), and then fetches of addresses 8, 9, 10 and 11. These fetches return values of 0x00, 0x00, 0x00 and 0x00. The DSP then stops fetching. I am assuming the DSP wanted to get my first AIS command of 0x5853590D for PLL setup. But this word is located at addresses 12, 13, 14 and 15 after I run the genAIS script. I have experimented with different settings for the genAIS command line, but end up with zeros at addresses 8-11 in each attempt where I have included my AIS configuration file. Maybe my assumption of the bootloader behavior is incorrect, and these zeroes are not the issue I am seeing in boot, but they do make me wonder as they are the last SPI reads I see upon each boot attempt.
Is there any TI documentation on the use of genAIS, other than the command-line usage information? Does TI have any examples of the appropriate command line invocation for genAIS with a configuration file and for 24-bit spimaster boot?
Thanks.
