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.
>
****************************************************************************
TI does not give a suggested value of RS to configurate the boot mode,just said"BOOTM[2:0]
are sampled following reset to configure the boot
mode for the DSP."
Now,1K Resistors are used instead of 10Ks to pull up/down BOOTM[2:0].
And one change has happened that the internal memory can not be read anymore when the simulator
is connected to the DSP.
Disconnecting the simulator, I can read the internal memory but not write as before.
-Ray