| ??? 06/19/08 02:05 Read: times |
#156025 - no.... Responding to: ???'s previous message |
Richard Erlacher said:
HDL's are popular with coders because they don't have to get their hands dirty, and don't have to commit themselves to anything they can't edit away. They are pretty good for expresing some functions, e.g. a binary to 7-segment encoder, which takes a 'B' size schematic if you draw out all the gates, yet it fits on half a page of VHDL. There are MANY other such functions, but there are also some that are very easily and clearly expressed in schematic diagrams. That is NOT the reason HDL's are popular. As I said, HDLs are popular because you simply cannot manage any reasonably sized project with schematics. They're too slow to draw and much more difficult to verify. HDL on the other hand is fast to implement and verify. What are you talking about "dirty hands"??? You're designing the exact same thing...one with a schematic and one with HDL. Your hands will be equally "dirty" no matter which tool you use. That's simply an invalid argument. Give me one example of something that is difficult to describe using HDL, but easy in a schematic. What real engineer is implementing a 7 segment encoder and calling it a day????? That's one extremely small part of some HUGE design. Who cares about something so simple?? Like I said, show me the schematic for the pipeline of a pentium 4. If it were the right tool people would use it. It's just not the right tool anymore. There is no reason at all not to be using HDL. Also, tell me how you're doing to do a behavioral simulation of your schematic? Does your standard cell library have schematic symbols with FO4, timing info, etc, etc?? I doubt it! By the way - even if you DID use schematics they'd still be compiled down by your CAD tools to.....HDL!!! I'm not sure that you can even make a schematic in design compiler... |
