开云体育

Hi,
I am building a demo board which will be interfaced with the PC by
means of Parallel Port in EPP mode. My guess is that I will require a
IEEE 1284 compatible controller on the board to communicate with the
PC.

Now the board has a FPGA on it. My question is whether

1) it will be easier to program the FPGA to act like a controller? or
2) Buy an off-the-shelf IEEE 1284 compatible controller and program
the FPGA to operate in conjuction with this controller??


I have made an independent search of parallel port controllers and
found that CD1283 is the only controller which has a lot of material
available about. However CD1283 has a bit complicated architecture.
Is there any other/simpler/probably cheaper controller available??


thanx
aditya

Aditya,
How complex do you need the interface to be? There are a lot of ways
around your particular issue.

For simple bit bashing (to control an LCD panel etc) - the Parallel port can
be hard wired to your board - a few simple lines of code to 0x378 (LPT1:
address), you can do pretty much anything.

For more complex applications you will probably need some extra support
chips - not neccessarily a controller, but enough to give you some
addressing. The simplest way (without too many external components) would be
to use TWO parallel ports, one for addressing and one for data - that way
you get 11 data lines x 2k worth of address space ... how much more could
you ask for?

If you only need the demo board to be interfaced to a PC, personally I would
probably slap a PIC or a HC811 processor on a board, use two pins for a
serial interface and let the processor do the translations for you.

Depends on the application you have in mind really.

Regards,


Jonathan

hey ,

won't the fpga controller slow...because it can't give the real-time
performance as the controller which you plan to make on it...(Just a
guess..never did a real FPGA programming...just simulated netlists.....)

Regards :-),

--himanshu sharma

Hi,

--- In Electronics_101@y..., "Jonathan Luthje" <jluthje@p...> wrote:

Aditya,
How complex do you need the interface to be? There are a lot of

ways

around your particular issue.

There r some requirements of the board. If we can sqeeze out the
maximum performance from the parallel port the better. We are involved
in BIDIRECTIONAL TRANSFER HERE.

Now we don't want to use centronics mode becoz it is unidirectional
only and we don't want ECP as it requires software compression and
commensurate decompression. So we r left with EPP.

Now let me repeat the question: whether I would require an ASIC to
control the protocol or should the FPGA take care of it??

thanx,
Aditya

There r some requirements of the board. If we can sqeeze out the
maximum performance from the parallel port the better. We are involved
in BIDIRECTIONAL TRANSFER HERE.

Fine - you're involved in bi-directional transfer - of what data? If you
actually posted the requirements of the board then perhaps we could help.
Without knowing what the actual I/O data requirements are ... (i.e. WHAT you
are transferring - or what you want to do with it)

If you insist on your refusal to post this information - use an ASIC and
figure it out yourself

Are you considering designing an ASIC to communicate with the
parallel port of a PC?

snip %<--------------------
We are involved

Hi,

--- In Electronics_101@y..., "manifold" <manifold_1@y...> wrote:

Are you considering designing an ASIC to communicate with the
parallel port of a PC?

Yes. We r communicating with Parallel Port of PC.

BTW somebody was asking for more information about this. So here
goes:

There is FPGA on the board which will be interfaced to PC by parallel
port. This requirement of Parallel Port interface cannot change. Now
we r configuring this FPGA means that there is about 2 MEGABITS of
data to be transferred really fast. We r using EPP mode for the
transfer. The FPGA will be configured and give the output back to
parallel port. Now will I require an ASIC to control the
communication between FPGA and Parallel Port??

regds,
Aditya.

snip %<--------------------
We are involved

in BIDIRECTIONAL TRANSFER HERE.

Now we don't want to use centronics mode becoz it is

unidirectional

only and we don't want ECP as it requires software compression and
commensurate decompression. So we r left with EPP.

Now let me repeat the question: whether I would require an ASIC to
control the protocol or should the FPGA take care of it??

thanx,
Aditya

You have an FPGA in the design. What is the FPGA doing that it
cannot communicate with a lowly parallel port?

--- In Electronics_101@y..., adityanewalkar@y... wrote:

Hi,

--- In Electronics_101@y..., "manifold" <manifold_1@y...> wrote:

Are you considering designing an ASIC to communicate with the
parallel port of a PC?

Yes. We r communicating with Parallel Port of PC.

BTW somebody was asking for more information about this. So here
goes:

There is FPGA on the board which will be interfaced to PC by

parallel

port. This requirement of Parallel Port interface cannot change.

Now

we r configuring this FPGA means that there is about 2 MEGABITS of
data to be transferred really fast. We r using EPP mode for the
transfer. The FPGA will be configured and give the output back to
parallel port. Now will I require an ASIC to control the
communication between FPGA and Parallel Port??

regds,
Aditya.

Do you mean slow compared to a parallel port or to an ASIC?

--- In Electronics_101@y..., "Himanshu Sharma" <hs_ramdev@y...> wrote:

hey ,

won't the fpga controller slow...because it can't give the real-time
performance as the controller which you plan to make on it...(Just a
guess..never did a real FPGA programming...just simulated

netlists.....)

Regards :-),

--himanshu sharma
----- Original Message -----
From: <adityanewalkar@y...>
To: <Electronics_101@y...>
Sent: Wednesday, October 31, 2001 12:33 PM
Subject: [Electronics_101] Parallel Port Interfacing


: Hi,
: I am building a demo board which will be interfaced with the PC by
: means of Parallel Port in EPP mode. My guess is that I will

require a

: IEEE 1284 compatible controller on the board to communicate with

the

: PC.
:
: Now the board has a FPGA on it. My question is whether
:
: 1) it will be easier to program the FPGA to act like a

controller? or

: 2) Buy an off-the-shelf IEEE 1284 compatible controller and

program

: the FPGA to operate in conjuction with this controller??
:
:
: I have made an independent search of parallel port controllers and
: found that CD1283 is the only controller which has a lot of

material

: available about. However CD1283 has a bit complicated

architecture.

: Is there any other/simpler/probably cheaper controller available??
:
:
: thanx
: aditya
:
: