My Dear Spartan-3A, Please Please WAKE UP!

After giving up the search for Xilinx supplied MicroBlaze reference designs for Xilinx Spartan-3A kit, I made the reference design using BSB in EDK 9.1SP1.

No problem encountered until the attempt to load the bitstream into Spartan-3A

Bitstream download succeeded, Done also OK. Reading back JTAG Status from impact tells me EVERYTHING is OK!

But... init LED is half-way dimmed and "AWAKE" LED is off, this behavior is the same no matter the "SUSPEND" input switch position. I have not enabled suspend in the design, so to my understanding the bitstream should come up alive?

But it doesnt. Is Spartan-3A in some undocumented deep sleep mode?

I was really hoping to see "Hello Spartan-3A" on the terminal, or at least the LEDs blinking. But all that happens is DONE=ON, AWAKE=OFF, INIT=30% dimmed.

I will fight again tomorrow, maybe I get some bright how to wake up Spartan-3A when I sleep.

Antti

Reply to
Antti
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Antti schrieb:

another PC, ISE 9.1 (no service pack)

Spartan-3A is working, INIT is not dimmed (OFF)

it is possible that with 9.1SP3 the FPGA also was actually configured ok (just the microblaze system das 100% dead), - I was irritated by the half-way lit INIT LED so I assumed FPGA is either misconfured or in some sleep state.

sorry for the confusion.

Antti

Reply to
Antti

It useally helps to sleep over a problem - the LED behaviour on Xilinx Spartan-3A is all explained:

with default bitgen options (unused IOB pulldown)

  • INIT LED "half-on"
  • AWAKE LED OFF

bitgen unused IOB pullup

  • INIT LED OFF
  • AWAKE LED "half-on"

bitgen unused IOB float

  • INIT LED OFF
  • AWAKE LED OFF

everything as it should be. I was just confused with the INIT LED yesterday, thats all. There was actual issue whatsoever, just my over-reacting because other issues.

Antti

Reply to
Antti

I am working with S3ASK, with microblaze and have no problema at all. Maybe you forgot to set the configuration switches to JTAG? I had that problem too!

Best regards

zara

Reply to
Zara

nono - there was NO PROBLEM..:) I was just confused that with default setting the INIT LED is 50% on state.. this is however NORMAL behaviour, I did not recognize that, and assumed something was wrong.

all things work ok on s3astarter, including MicroBlaze - well without DDR2 support :(

Antti

Reply to
Antti

I have not tried yet the DDR2. What is the problem with mch_opb_ddr2 controller? It is a PREFERRED IP type, I thought it should work.

I will try to take a look at it, anyway..

Best regards,

Zara

Reply to
Zara

Hi Zara,

I hope mch_opb_ddr2 will work, but I have been wondering why such demo design is not available - this could be an indication that the "out of the box" DDR2 IP core will not work on Spartan-3A, so I am in a waiting mode, hoping for someone to confirm the useability of EDK DDR2 ipcore on Xilinx Spartan-3A starterkit board.

Antti

Reply to
Antti
[snip]

Antti, I'm in the exact same spot as you are, I just got a Spartan-3A starter kit to test DDR2 in preparation for a custom board design.

Can you share your EDK design with the group? Please also post updates if you manage to get DDR2 to work.

I did a very quick test yesterday, and the place and route step complained that it couldn't meet the timing. When creating the design with BSB it stated that you have to run at 100MHz for the DDR2 controller to work. I haven't gotten further than that, I hope I missed something basic.

/ Chris

Reply to
lagerstrom

I am now tryiong to start the DDR2 with Microblaze. It will not achieve timnog constarints with 100MHz system clock, but it will achieve them with 66.666MHz system clock! More to come...

Zara

Reply to
Zara

[..]

its VERY hard to meat 100MHz timings even in V4 or V5 so I no wonder the EDK-DDR2 design in Spartan-3A doesnt want to meat 100MHz timings.

also check the Spartan3A "product notification" and your PCB rev. if you have REV C you need to solder bridge 2 ferrites to get the DDR2 to work at higher clock rates.

Antti

Reply to
Antti

Done it. But there is something with one of my SDK installations (the one I use to communicate with S3 Lti, so my progress has stopeed for a littel while). Hope it will restart soon!

Zara

Reply to
Zara

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