cpld programming

hi embedded gurus i m working on a project which needs cpld
programming,i want to interface cpld with avr microcontroller

kuldeep singh wrote:
> hi embedded gurus i m working on a project which needs cpld
> programming,i want to interface cpld with avr microcontroller
Sounds interesting.

"kuldeep singh" <> skrev i meddelandet
news: oups.com...
> hi embedded gurus i m working on a project which needs cpld
> programming,i want to interface cpld with avr microcontroller
>


Maybe you should look at the FPSLIC which contains an AVR and an FPGA?

--
Best Regards
Ulf at atmel dot com
These comments are intended to be my own opinion and they
may, or may not be shared by my employer, Atmel Sweden.

On 19 Jan 2005 00:31:15 -0800, "kuldeep singh" <>
wrote in comp.arch.embedded:

> hi embedded gurus i m working on a project which needs cpld
> programming,i want to interface cpld with avr microcontroller

We're doing a system where not only the firmware, but also the CPLDs,
have to be reprogrammable in system on site.

We have three different board types, one based on Atmel's AT91RM9200
part, and two based on TI's TMS320F2912. All the boards have a
Lattice CPLD on them.

We built a circuit with tri-state buffers so that the JTAG pins of the
CPLD normally connect to a JTAG header for initial programming in
manufacture, but the ARM or DSP firmware, under program control, can
control the enables of the tri-state buffers so that the CPLD JTAG
pins are connected to the SPI port and one I/O pin of the controller
or DSP.

Of course, your main processor or DSP has to be able to operate in a
mode where it can receive a new CPLD image over some interface and
erase and reprogram it without needing any of the functionality that
is implemented in the programmed CPLD.

Once you get the programming code debugged, it works quite well.

--
Jack Klein
Home: http://JK-Technology.Com
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Nice idea but not that easy to implement...
Beware of the fact that the CPLD is disconnecting their pins (what is
the state then pullup, pulldown, tristate ?)
when entering the (re)programming state. Not to mention the
"reconnecting" (transient) state you can get...
("preload" state is your friend).
And don't forget that OLD!!! tools can generate a much smaller CPLD
config data volume... for the same functions...;-)
Hope it helps
Bibico

kuldeep singh wrote:

> hi embedded gurus i m working on a project which needs cpld
> programming,i want to interface cpld with avr microcontroller