Hi,
After finally getting the HPI port on the DM6467 to work (following the discovery that the descriptions of the HCNT0 and HCNT1 lines in the HPI users guide is exchanged), I still cannot get the auto increment function to work as I expected.
I need to interhangebly read and write data starting from a single address. Both the HPIAW and HPIAR registers should be incremented with every read / write (i.e., they should always be the same. I want to read from address N, write to address N+4, read from N+8, write to N+12 etc.). I therefore disable dual HPIA mode in the HPIC register. I then program the start address into both HPIAW and HPIR (from the DSP, while the DSP has control of the HPIA and HPIC). I can see with the JTAG-ICE that both registers are the same. I than give control of the HPIC and HPIA reigsters to the host and trigger the host to start the read/write process by setting HINT. The host reads one word (with auto increment) and then writes one word (with auto-increment).
I would expect the HPIAW register to increment after the host read command, but it does not. It remains unchanged. It is, however, correctly incremented after the host write. The HPI Users Guide states that if DUALHPIA is set to 0, then both HPIAR and HPIW are incremented after either a read or a write. I have, just for a test, enabled dual HPIA mode, the results are identical. It almost seems as if clearing the DUALHPIA bit still results in dual HPIA mode. Am I wrong in my interpretation or am I doing something wrong?
Regards,
Niki