Scott,
| 3.2.2.3 clock_times
| ===================
|
| Vector to return clock times. The clock times are referenced to
the start
| of the simulation (the first AMI_GetWave call). The time is always
| greater or equal to zero. The last clock is indicated by putting
a value
| of -1 at the end of clocks for the current wave sample. The
clock_time
| vector is allocated by the EDA platform and is guaranteed to be
greater
| than the number of clocks expected during the AMI_GetWave call.
The clock
| times are the times at which clock signal at the output of the
clock
| recovery loop crosses the logic threshold. It is to be assumed
that the
| input data signal is sampled at exactly one half clock period
after a
| clock time.
We’ve always taken the phrase:
| Vector to return clock times. The clock times are referenced to
the start
| of the simulation (the first AMI_GetWave call).
We’ve always taken that to mean that clock times maintain a consta
nt time zero reference across Getwave calls (i.e. not referenced t
o the start of the block). You can argue that isn’t stated explic
itly enough, but that’s my understanding.
Suggestions on wording to make things clearer are welcome and
appreciated.
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-
bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow
Sent: Friday, March 26, 2010 5:34 PM
To: Wenyi.Jin@xxxxxxx
Cc: vladimir_dmitriev-zdorov@xxxxxxxxxx; ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: FW: Question on clock_times
The specification is not clear concerning the meaning of the
clock_times vector.
I see two valid interpretations:
Clock_times are relative to the start of the current block
clock_times are relative to the start of the 1st block
I do not see this defined in the specification. If it is, then
please point me to the section.
--
Scott McMorrow
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
(401) 284-1827 Business
(401) 284-1840 Fax
http://www.teraspeed.com
Teraspeed® is the registered service mark of
Teraspeed Consulting Group LLC
Jin, Wenyi wrote:
for CASE 2 and CASE 3, how can clock_time begin from 0? It is
already 2nd block.
If some call generate valid clock_time, some not, that means DLL
has to track
the information like block number to decide from which block begin
return clock time.
DLL can always return clock time even CDR is in lock-in stage, it
is the EDA tool that
Specified after how many UI or block, to make use of clock_time.
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-
bounce@xxxxxxxxxxxxx] On Behalf Of Dmitriev-Zdorov, Vladimir
Sent: Friday, March 26, 2010 2:08 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: FW: Question on clock_times
Please clarify if the following clock time patterns are legitimate
when performing several GetWave calls (for simplicity/brevity, let
’s assume that we have only 10 bits per call and will use integers
instead of small double values). Which of the following 3 cases a
re allowed?
CASE 1:
After the 1-st call:
0 1 2 3 4 5 6 7 8 9 -1
After the 2-nd call:
10 11 12 13 14 15 16 17 18 19 -1
After the 3-rd call:
20 21 22 23 24 25 26 27 28 29 -1
etc.
CASE 2:
After the 1-st call:
-1 # # # # # # # # # # // First call does not
generate clocks
After the 2-nd call:
0 1 2 3 4 5 6 7 8 9 -1
After the 3-rd call:
10 11 12 13 14 15 16 17 18 19 -1 // time increment continued
from the last call
etc.
CASE 3:
After the 1-st call:
-1 # # # # # # # # # #
After the 2-nd call:
0 1 2 3 4 5 6 7 8 9 -1
After the 3-rd call:
0 1 2 3 4 5 6 7 8 9 -1 // i.e. always start from zero
etc.
-----Original Message-----
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-
bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Friday, March 26, 2010 2:38 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] FW: Question on clock_times
Kumar,
So are you saying that the vector can begin
with a bunch of -1 and then have valid number
later in the vector? Lie this:
-1 -1 -1 -1 # # # # # # # # -1 -1 -1 -1
If this is true, is it also true that you can
have alternating -1 and good values in the
vector? Like this?
-1 -1 -1 -1 # # # # # # # # -1 -1 -1 -1 -1 -1 -1 -1 # # # # # # # #
-1 -1 -1 -1
Arpad
==============================================
From: C. Kumar [mailto:kumarchi@xxxxxxxxx]
Sent: Friday, March 26, 2010 3:29 PM
To: Muranyi, Arpad
Subject: Re: [ibis-macro] Question on clock_times
arpad:
let me take shot at this
1. Yes -1 indicates end of clock vector
2. clock vector is the clocks associated with the particular wave
vector in the particular getwave call.
3. some models can have delayed start for returning a clock vector.
Once a legitimate clock vector is returned , the eda tool is
expected to use that information to sample the wave
returned by the getwave call. Other wise the eda tool may rely on
its own devices to sample the wave, (usually this is an 'ideal'
clock)
4. some models may modify the wave form but may never return a
clock vector. (i.e -1 in the first position)
From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
To: ibis-macro@xxxxxxxxxxxxx
Sent: Fri, March 26, 2010 4:08:16 PM
Subject: [ibis-macro] Question on clock_times
Hello AMI experts,
I would like to ask a question about the clock_times vector.
The spec says that "The last clock in indicated by putting a
value of -1 at the and of clocks for the current wave sample".
We got a DLL from a vendor which seems to fill the vector
for the first few GetWave calls with -1 and then it starts
filling it with good numbers.
What is the interpretation of the specification? First,
does the above text refer to the entire vector, or each
little section independently that a single GetWave call
returns?
If it is for the entire vector, then having -1 in the first
few thousand locations would mean that everything else
after that is garbage, correct?
If it is per GetWave call, is the EDA tool expected to
assemble something from bits and pieces that are returned
by the various GetWave calls?
Thanks,
Arpad
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--
Scott McMorrow
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
(401) 284-1827 Business
(401) 284-1840 Fax
http://www.teraspeed.com
Teraspeed® is the registered service mark of
Teraspeed Consulting Group LLC
