[ibis-macro] Re: AMI-init should pass modified IR to getwave....
- From: Taranjit Kukal <kukal@xxxxxxxxxxx>
- To: "'msteinb@xxxxxxxxxx'" <msteinb@xxxxxxxxxx>, "'ibis-macro@xxxxxxxxxxxxx'" <ibis-macro@xxxxxxxxxxxxx>
- Date: Thu, 14 Jun 2012 20:05:05 +0530
Hi Mike,
It is not about passing the IR from init to getwave, it is about getting the
waveform convoluted with modified-IR in getwave. This saves unnecessary
convolution of IR in getwave and leaves this process to EDA tool that does the
appropriate sampling and math. This also brings consistency.
Hope I made myself clear.
Rgds
From: Mike Steinberger [mailto:msteinb@xxxxxxxxxx]
Sent: Thursday, June 14, 2012 07:32 PM
To: ibis-macro@xxxxxxxxxxxxx <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] Re: AMI-init should pass modified IR to getwave....
Kukal-
You can always store the impulse responses you want inside the memory pointed
to by the model's memory handle.
That is, inside the header file:
typedef struct {
...
double *internal_impulse_response,
...
} MyModel;
Inside AMI_Init():
MyModel *self;
self = (MyModel*)malloc( sizeof(MyModel) );
memory_handle = (void*)self;
self->internal_impulse_response = (double*)malloc( row_size*sizeof(double) );
//Set the value of self->internal_impulse_response however you want.
Inside AMI_GetWave():
MyModel *self = (MyModel*)memory_handle;
//Use self->internal_impulse_response however you like
I'm pretty sure there are other model developers who have been using this
technique successfully now for several years.
Good luck.
Mike Steinberger
On 06/14/2012 01:04 AM, Taranjit Kukal wrote:
Hi All,
When I was implementing AMI model, I found a situation where it was important
that Rx ami_init needed to pass modified-IR to getwave function.
Reason was that Chip-RDL-routing was available as Impulse-Responses.
Removal for “Use_Init_Output” to make Statistical-flow independent of
Transient-flow, is going to break the original intent where init and getwave
were supposed to work in conjunction with each other handling linear and
non-linear filtering portions respectively (as shown below)
[cid:part1.05090509.00000704@sisoft.com]
I would go back to Arpad’s suggestion (year 2010) for having two
Impulse-responses coming out of ami_init
- One that goes to EDA tool for statistical flow
- One that gets passed to getwave to allow splitting of
modeling-effort across init and getwave and make things easy for linear filters.
BIRD120 was brought up that deprecates use of “use_init_output” with a view to
keep statistical and time-domain simulations independent. But as I think more,
we need to allow both capabilities. It absolutely does not make sense to
implement simple linear filters within getwave when we can convolute the
filter-IR with channel-IR. We should take all steps to make modeling easy and
ensure enough flexibility.
This way, we cover both the scenarios – those who want to leverage init as
complement to getwave and those who want to keep statistical-flow purely
independent. Since this does not bring any disadvantage, I strongly feel that
we all re-consider outputting two modified-IRs out of init function – one for
statistical-flow and another one to complement getwave filtering.
Rgds
..kukal
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