2009-04-10 10:20:03 FPGA programming in uClinux and uBoot.
V Hemanth Kumar (INDIA)
Message: 72509
We have thought to interface FPGA to bf527 through SPORT and gpios pins on our custom board (is in design phase). This is very much similar to the interface provided by Blackfin FPGA EZ Extender.
I found a code fpga_loader.c in the SVN which uses the spidev to program the FPGA.
I have few questions:-
1. Which is the best and reliable way to connect the FPGA, is it through SPORT or SPI interface? Is there any other better way to interface FPGA to Blackfin?
2. Is there a code in the uClinux distribution which programs the FPGA interfaced over SPORT?
(A code something similar to one provided by VDSP in "\Blackfin\Examples\FPGA EZ-EXTENDER" for programming the Blackfin FPGA EZ Extender. The VDSP code programs the FPGA through SPORT ).
3. Does uBoot have a utility to program FPGA at the command line?
Please provide your valuable inputs on these points.
Thanks.
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2009-04-10 12:00:46 Re: FPGA programming in uClinux and uBoot.
Mike Frysinger (UNITED STATES)
Message: 72512
usually the most important question is throughput ... how fast do you actually need the fpga interface to be ?
if the answer is "not really fast at all", then using GPIOs and SPI is a safer bet as it's a much simpler interface to work with -- both in terms of the physical lines and the linux / u-boot software interface
if you need speed, then the sport is your only real answer. and in that case, you'll probably have to write both the linux and u-boot interfaces
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2009-04-14 10:37:20 FPGA programming in uClinux and uBoot.
Michael Hennerich (GERMANY)
Message: 72640
1)
How fast do you need fast?
I wrote the fpga_loader.c utility.
It configures (Slave Serial Mode) a Xilinx Spartan 3 in approx. one
second.
I decided to use SPI since there is a generic user space device
available.
2)
Not that I'm aware of.
3)
Yes
- there is such infrastructure in u-boot.
-Michael