IDMA of ADSP-218x

Started by Eric Chan November 30, 2000
I am design the IDMA interface to ADSP-218x, the host need access the
PM/DM of DSP chip via IDMA.
It is easy to understand how to access the DM, because the DM is
16-bits wide, but when the host need access the PM, I meet a question,
the PM is 24-bits wide when the IDMA bus IAD is 16-bits wide, then to
access a addressable PM word, 2 IAD will be send. The host need wait
the IACK_ assert, then send out the 1st IAD (16 bits of the PM), then
is the 2nd AD (another 8 bits of PM), I am not clear whether the
interface need wait for the IACK_ assert again to send out the 2nd IAD.
--
Eric Chan <


I am design the IDMA interface to ADSP-218x, the host need access the
PM/DM of DSP chip via IDMA.
It is easy to understand how to access the DM, because the DM is
16-bits wide, but when the host need access the PM, I meet a question,
the PM is 24-bits wide when the IDMA bus IAD is 16-bits wide, then to
access a addressable PM word, 2 IAD will be send. The host need wait
the IACK_ assert, then send out the 1st IAD (16 bits of the PM), then
is the 2nd AD (another 8 bits of PM), I am not clear whether the
interface need wait for the IACK_ assert again to send out the 2nd IAD.
--
Eric Chan <