Rookie questions about Orcad/Protel simulation

[Ghazan Haider]

I play with electronics as a hobby and am used to using Circuitmaker's
spice simulations with transistor-based applications, and I've etched
a few PCBs at home. The digital arena however is confusing.

Q1) Can digital parts be simulated? I have heard of the VHDL language
and some parts like DRAMs have VHDL sources. Can these be used to
check if the DRAM part if wired correctly will work as expected?

Q2) If true, have MCUs and MPUs been emulated using VHDLs? Whats the
upper limit of VHDL simulation... the PIC MCUs? The Athlon64?

Q3) Many parts from Sharp, Philips and Cirrus do not have such VHDL
sources online. Do they sell them? Do they come in packs sold by other
vendors? Are they too complicated for VHDL simulation?

Q4) Does VHDL simulation take into account the analog portions as well
such as too high a frequency, resistors on bus lines, capacitance
effects on very closely etched boards?

Q5) Are there incompatible versions of VHDL sources in circulation I
have to watch out for when trying to gather sources for simulating a
project?

Q6) Can you have FPGAs programmed on the go and functioning all in
VHDL simulation?

 

[Leon Heller]

"Ghazan Haider" <ghazan@ghazan.haider.name> wrote in message
news:2f57764a.0307230841.32a2d84e@posting.google.com...

I play with electronics as a hobby and am used to using Circuitmaker's
spice simulations with transistor-based applications, and I've etched
a few PCBs at home. The digital arena however is confusing.

Q1) Can digital parts be simulated? I have heard of the VHDL language
and some parts like DRAMs have VHDL sources. Can these be used to
check if the DRAM part if wired correctly will work as expected?

Yes.

Q2) If true, have MCUs and MPUs been emulated using VHDLs? Whats the
upper limit of VHDL simulation... the PIC MCUs? The Athlon64?

VHDL implementations of PICs, etc. are available. If someone did this for
the Athlon or Pentium (difficult) they would probably get sued.

Q3) Many parts from Sharp, Philips and Cirrus do not have such VHDL
sources online. Do they sell them? Do they come in packs sold by other
vendors? Are they too complicated for VHDL simulation?

They buy their IP from ARM.

Q4) Does VHDL simulation take into account the analog portions as well
such as too high a frequency, resistors on bus lines, capacitance
effects on very closely etched boards?

No.

Q5) Are there incompatible versions of VHDL sources in circulation I
have to watch out for when trying to gather sources for simulating a
project?

VHDL is quite standard.

Q6) Can you have FPGAs programmed on the go and functioning all in
VHDL simulation?

You have to distinguish between VHDL used for simulation and for synthesis.
The latter is the process of implementing the design on actual hardware,
like an FPGA or ASIC.

Leon
--
Leon Heller, G1HSM
leon_heller@hotmail.com
http://www.geocities.com/leon_heller

 

[Ghazan Haider]

Thanks. That clarified many things.

What (lowcost) application would you recommend for VHDL simulation and
PCB design? Ive heard of Orcad and Protel and non-graphic GNU tools.
Are the GNU tools my best option?

 

[Leon Heller]

"Ghazan Haider" <ghazan@ghazan.haider.name> wrote in message
news:2f57764a.0307240545.6e5ff4a2@posting.google.com...

Thanks. That clarified many things.

What (lowcost) application would you recommend for VHDL simulation and
PCB design? Ive heard of Orcad and Protel and non-graphic GNU tools.
Are the GNU tools my best option?

You can download free VHDL tools from the Altera web site. Xilinx Webpack is
also free, but doesn't include simulation; you have to download the free
limited version of Modelsim for that. Both these toolsets include synthesis
for their FPGAs.

A very good VHDL compiler and simulator is Symphony/Sonata from:

http://www.symphonyeda.com/

A free working demo is available.

Leon
--
Leon Heller, G1HSM
leon_heller@hotmail.com
http://www.geocities.com/leon_heller