To migrate from 'e' based verification environment to sytem verilog is the possible biggest trend in the coming days. Especially during and immediately after the recession days. So any work done in automating or semi-automating the translation from e to SV could reap benefits.
Beginning from here, let me see how much can I contribute. It is a scary project, but could it be any scarier than this classic horror movie.
youtube link to one of finely crafted scene by Stanley Kubrick and wonderfully enacted by Jack Nicholson
The following points on filters can only help to recall some of the basics and might provide the direction for further study. This is not a coherently written article but only a brief collection of interesting points that would explain filters in general.
Analogue filters provide the required filtering using op-amps, capacitors etc and Digital filters uses a digital processors chip (like DSP)
In digital filters, an analog input is ADCed (sampled and quantized/digitized), then this is input to a processor, which perform some calculation on this input like xn+xn-1 or xn + yn-1, where x is input & y is output. The (filtered) result is then fed to DACs which convert them back to analog form.
If output is directly dependent on present and/or previous inputs, then this is called non-recursive filter or FIR
If output is dependent not only input values but also on previous outputs, then this is called recursive filter or IIR.
IIR - theoretically produces an infinite response to an impulse input (value 1 at time 0.) Practically, the output fades to 0 after a finite period!
FIR - Produces a response for finite period for the same impulse input
From the definitions it appears that IIR (recursive) filters require more calculation than IIR? No, actually FIR requires more calculation (less order filters) than IIR fitlers to achieve the same freq response characteristics Eg of recursive filter: y0 = x0 + y-1 y1 = x1 + y0 y2 = x2 + y1 and so on.
So, y9 = x9 + y8 for IIR calculation but for non-recursive, y9= x0+x1+x2+x3+x4+x5+x6+x7+x8+x9 (all prev inputs should be saved in memory.) Thus FIR requires more calc than IIR.
For IIR, order is the number of largest previous input or previous output. yn = xn + yn-1 is first order eg. yn = xn-1 + xn-2 +yn-1 +yn-2 is second order eg Ex of zero order IIR filter?? Impossible becoz yn = xn (is not FIR) and yn = yn is linear device and not a kind of filter by any definition.
Transfer function: Puts the filter expression in compact convenient form (op/ip) From this we can derive many characteristics of a filter like freq response. so yn = xn + yn-1 can be represented as
yn = xn + z^-1yn (1-z^-1)yn = xn TF = yn/xn = 1/(1-z^-1) of IIR filter
For FIR, TF doesn't contain any denominator. eg. yn = a0 + a1z^-1+ a2z^-2
Starting with Mahmud of Ghazni (971-1030AD), Urdu grew to lay its roots in the North West and Central India. It evolved over the last two centuries and soon became a base for poetry in the North of India and Pakistan. The mogul courts used basically two languages, Persian or Farsi and the religious language which was Arabic. The sultans themselves spoke Turkish (or a Turkic variant). Urdu or Ordu means tent or army and Urduca was thus the language of the army. This 'Lashkarai Zaban' or Zaban e Ordu was needed for the armies of India, armies that often comprised soldiers with various native mother tongues from diverse regions of the Middle East & India. Hence, Urdu evolved to become the chosen language to address these soldiers as it abridged several base languages
Asked how terrorism might be counteracted, Frederick Forsyth says: 'The West can only form an "alliance of the civilized" and work on the five fronts on which all covert or "cold" wars are fought: diplomatic, financial, that of lethal action--and, most importantly, by using intelligence and psychological means, i.e. propaganda, persuasion, hearts and minds. You cannot defeat a modern, fanatical terrorist enemy without winning all five.' [Source: 'Note on Author' section in the book The Afghan]
