Lingbo-
>      Which 55x DSP are you using?
>
>      We always use multiplexed mode for HPI. However, for non-multiplexed mode
>      I think
>      you still need to connect HCNTL1, which is not in your list above. Both
>      HCNTL0 and
>      HCNTL1 have to be connected to allow access to four (4) possible HPI
>      registers:
>
>      -HPIC
>      -HPIA
>      -HPID no autoincrement
>      -HPID autoincrement
>
>      In the C5502 data sheet, Figure 3-5 shows both HCNTLx connected for
>      non-multiplexed
>      HPI. If you're not using 5502, then possibly look for a similar figure in
>      other 55x
>      data sheets.
>
>      Also, do you have HPIENA active? What about pull-up/down Rs on GPIOx
>      lines that
>      select HPI mode at Reset?
>
>      -Jeff
>
> Hi,Jeff,
> I'm using 5510 v2.2,which is not supporting multiplexed mode for HPI anymore.In
> non-multiplexed mode,HCNTL1 is used as HA1(ADDRESS 1).Only HCNTL0 is configured to
> selecte the HPID/HPIC register.
> There may be lots of  differences between  5510 and 5502. I can not find  any pin
> named HPIENA.
> DSP is powered up with BOOTM[3:0] = 1101,which selects the EHPI Boot Mode .Each
> GPIO of  these  is pulled up/down by a 10K Rs.
> Thank you for your email.

Ok 5510 and not 5502.  Then your hook-up may be Ok.  Are you sure 10k is strong
enough value for pull-up/down Rs?  You might check the data sheet closely.  Sometimes
TI recommends stronger value, such as 1k.

One debug suggestion -- read HPIC first.  That's a known value, so it's easier to
test.  Then run some small DSP code (via JTAG) that sets HINT bit, and verify you can
read the 1 bit change.  If your HPI circuit doesn't allow you to read, then obviously
you can't write.

-Jeff

PS. Please post to the group, not to me.