Hi Lisa: I think that what I wrote is consistent with what we already have in D4 on p. 322 and which results when we apply the change of 1731. We can discuss this further in the meeting tomorrow. J.H. > X-MimeOLE: Produced By Microsoft Exchange V6.5 > Content-class: urn:content-classes:message > Date: Mon, 11 Feb 2008 18:22:40 -0500 > X-MS-Has-Attach: > X-MS-TNEF-Correlator: > Thread-Topic: 1698 > Thread-Index: AchstJnq2bU6SFbrSfmDTMDyCoQLuQATsnVQ > From: "Lisa Piper" <piper@cadence.com> > Cc: <doron.bustan@intel.com>, <eduard.cerny@synopsys.com>, > <yaniv.fais@freescale.com>, <dmitry.korchemny@intel.com>, > <Manisha_Kulshrestha@mentor.com>, <johan.martensson@jasper-da.com>, > <erik.seligman@intel.com>, <bassam.tabbara@synopsys.com>, > <thomas.thatcher@sun.com> > X-Received: By mx-sanjose2.Cadence.COM as m1BNMdWG009667 at Mon Feb 11 15:22:40 2008 > X-OriginalArrivalTime: 11 Feb 2008 23:22:48.0709 (UTC) FILETIME=[03DC4350:01C86D05] > > This is a multi-part message in MIME format. > > ------_=_NextPart_001_01C86D04.FDF32B1D > Content-Type: text/plain; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > Hi John, > > =20 > > I reviewed the 1698. This is completely different than what I thought > was desired for sampled value operation: > > =20 > > The value of the expression sampled in the Preponed region of the > current timestep is compared to the value of the expression sampled in > the Preponed region of the most recent strictly prior timestep in which > the clocking event occurred. Here, the current timestep refers to the > simulation timestep > > in which the function is called. > > =20 > > As another example, > > always_ff @(posedge clk1) > > reg1 <=3D $rose(b,@(posedge clk2)); > > =20 > > Here, reg1 is updated in each timestep in which posedge clk1 occurs, > using the value returned from the $rose sampled value function in that > timestep. $rose compares the sampled value of the LSB of b from the > current timestep (one in which posedge clk1 occurs) with the sampled > value of the LSB of b in the strictly prior timestep in which posedge > clk2 occurs. > > =20 > > I had pictured $rose(b,@(posedge clk2)) as comparing two values, both of > which occurred at posedge clk2. The way you have written it, we compare > the current value at posedge clk1 with the previous sampled value when > clk2 occurred. > > =20 > > This was not my understanding of what was desired though it is another > possible implementation. > > =20 > > As an aside, I have noticed that LSB (and lsb) refers to least > significant bit in most places of the LRM but on page 207 it is least > significant byte. That has caused some confusion, though it is obvious > to me. Should we specify it? > > =20 > > Lisa > > =20 > > -----Original Message----- > From: John Havlicek [mailto:john.havlicek@freescale.com]=20 > Sent: Monday, February 11, 2008 8:47 AM > To: sv-ac@eda.org > Cc: doron.bustan@intel.com; eduard.cerny@synopsys.com; > yaniv.fais@freescale.com; john.havlicek@freescale.com; > dmitry.korchemny@intel.com; Manisha_Kulshrestha@mentor.com; > johan.martensson@jasper-da.com; Lisa Piper; erik.seligman@intel.com; > bassam.tabbara@synopsys.com; thomas.thatcher@sun.com > Subject: 1698 > > =20 > > Hi Folks: > > =20 > > On Friday I posted a revision of 1698 that I think is > > in good shape. > > =20 > > I believe that Ed's characterization of the RTL was correct, > > but it is not necessary to talk about it in order to define > > what the sampled value functions mean. Since it was raising > > concern, it has been deleted. > > =20 > > I plan to call for e-mail vote on this for our next review=20 > > round. > > =20 > > J.H. > > > ------_=_NextPart_001_01C86D04.FDF32B1D > Content-Type: text/html; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > <html xmlns:o=3D"urn:schemas-microsoft-com:office:office" = > xmlns:w=3D"urn:schemas-microsoft-com:office:word" = > xmlns:st1=3D"urn:schemas-microsoft-com:office:smarttags" = > xmlns=3D"http://www.w3.org/TR/REC-html40"> > > <head> > <meta http-equiv=3DContent-Type content=3D"text/html; = > charset=3Dus-ascii"> > <meta name=3DGenerator content=3D"Microsoft Word 11 (filtered medium)"> > <o:SmartTagType = > namespaceuri=3D"urn:schemas-microsoft-com:office:smarttags" > name=3D"PersonName"/> > <!--[if !mso]> > <style> > st1\:*{behavior:url(#default#ieooui) } > </style> > <![endif]--> > <style> > <!-- > /* Font Definitions */ > @font-face > {font-family:"MS Mincho"; > panose-1:2 2 6 9 4 2 5 8 3 4;} > @font-face > {font-family:"\@MS Mincho"; > panose-1:0 0 0 0 0 0 0 0 0 0;} > /* Style Definitions */ > p.MsoNormal, li.MsoNormal, div.MsoNormal > {margin:0in; > margin-bottom:.0001pt; > font-size:12.0pt; > font-family:"Times New Roman";} > a:link, span.MsoHyperlink > {color:blue; > text-decoration:underline;} > a:visited, span.MsoHyperlinkFollowed > {color:purple; > text-decoration:underline;} > p.MsoPlainText, li.MsoPlainText, div.MsoPlainText > {margin:0in; > margin-bottom:.0001pt; > font-size:12.0pt; > font-family:"Courier New";} > @page Section1 > {size:8.5in 11.0in; > margin:1.0in 32.35pt 1.0in 32.35pt;} > div.Section1 > {page:Section1;} > --> > </style> > > </head> > > <body lang=3DEN-US link=3Dblue vlink=3Dpurple> > > <div class=3DSection1> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>Hi John,<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>I reviewed the 1698. This is completely different than what I = > thought was > desired for sampled value operation:<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'>The value of the expression sampled in the = > Preponed > region of the current timestep is compared to the value of the = > expression > sampled in the Preponed region of the most recent strictly prior = > timestep in > which the clocking event occurred. Here, the current timestep refers to = > the > simulation timestep<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'>in which the function is = > called.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'>As another = > example,<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'> always_ff @(posedge = > clk1)<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'> &nbs= > p; reg1 > <=3D $rose(b,@(posedge clk2));<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'>Here, reg1 is updated in each timestep in = > which > posedge clk1 occurs, using the value returned from the $rose sampled = > value > function in that timestep. $rose compares the sampled value of the LSB = > of b > from the current timestep (one in which posedge clk1 occurs) with the = > sampled > value of the LSB of b in the strictly prior timestep in which posedge = > clk2 > occurs.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText style=3D'margin-left:.5in'><font size=3D3 = > face=3D"Courier New"><span > style=3D'font-size:12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>I had pictured $rose(b,@(posedge clk2)) as comparing two values, = > both > of which occurred at posedge clk2. The way you have written it, we = > compare the > current value at posedge clk1 with the previous sampled value when clk2 > occurred.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>This was not my understanding of what was desired though it is = > another > possible implementation.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>As an aside, I have noticed that LSB (and <i><span = > style=3D'font-style: > italic'>lsb</span></i>) refers to least significant bit in most places = > of the > LRM but on page 207 it is least significant byte. That has caused some > confusion, though it is obvious to me. Should we specify = > it?<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>Lisa<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>-----Original Message-----<br> > From: John Havlicek [mailto:<st1:PersonName = > w:st=3D"on">john.havlicek@freescale.com</st1:PersonName>] > <br> > Sent: Monday, February 11, 2008 8:47 AM<br> > To: sv-ac@eda.org<br> > Cc: doron.bustan@intel.com; eduard.cerny@synopsys.com; > yaniv.fais@freescale.com; <st1:PersonName = > w:st=3D"on">john.havlicek@freescale.com</st1:PersonName>; > dmitry.korchemny@intel.com; Manisha_Kulshrestha@mentor.com; > johan.martensson@jasper-da.com; Lisa Piper; <st1:PersonName = > w:st=3D"on">erik.seligman@intel.com</st1:PersonName>; > bassam.tabbara@synopsys.com; thomas.thatcher@sun.com<br> > Subject: 1698</span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>Hi Folks:<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>On Friday I posted a revision of 1698 that I think = > is<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>in good shape.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>I believe that Ed's characterization of the RTL was = > correct,<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>but it is not necessary to talk about it in order to = > define<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>what the sampled value functions mean. Since it was = > raising<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>concern, it has been deleted.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>I plan to call for e-mail vote on this for our next review = > <o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>round.<o:p></o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'><o:p> </o:p></span></font></p> > > <p class=3DMsoPlainText><font size=3D3 face=3D"Courier New"><span = > style=3D'font-size: > 12.0pt'>J.H.<o:p></o:p></span></font></p> > > </div> > > </body> > > </html> > > ------_=_NextPart_001_01C86D04.FDF32B1D-- -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Mon Feb 11 18:43:11 2008
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