Forum Discussion
Honored ContributorAlt_asmi
Hi,
I have a CyCIII connectet to a serial configuration device. I´m able to configure the CYC III with active serial. Now I want to access the Flash with the ALT_ASMI_Parallel_Interface. I pulled the signal read_sid to HIgh... and about 40 clock cycs later the busy signal (ouptput) goes to low. The problem is that the epcs_id (8 bit output) is allways 0xFF. What could there be wrong? clk_in frequency of alt_asmi is 12.5Mhz from a PLL. Thanks Chris16 Replies
Altera_ForumI too have a similar issue with a cyc3 . Probing the EPCS16 shows that after FPGA configuration the EPCS nCS signal goes low. When the ASMI function is used to preform a read the nCS is driven high when the operation code is sent out. Sort of behaves as though the nCS is inadvertantly inverted in the megafunction.
- Altera_Forum
The altera megafunction shall work with EPCS devices. I do not have an EPCS device but a ordinary serial flash from STM.
If you have a standard EPCS device this shall work for sure. I only have tested it in simulation and not in hardware. Do you probing in hardware? Ensure that you have selected the right EPCS device in the megacore wizard. In hardware you have to ensure to use the correct pins on the cylone III device. - Altera_Forum
Yep, I'm using the correct device n the megafunction (epcs16). It's failing in the actual hardware where as I mentioned earlier the nCS behaves as though it's being inverted. The traces below show the operation during a read through the asmi function. The signals from top to bottom are conf_done, asdi, nCS, data, dclk.
http://patobravo.smugmug.com/photos/218312442-L.jpg - Altera_Forum
if the measurement is OK, the nCS should be inverted. If you are sure that this signal comes directly from the megacore, you should ask the altera technical support with a request on the homepage. This requests are often replied fast. You can also post your solution here.
You can also try to invert the nCS signal by your self and check what happens than :) - Altera_Forum--- Quote Start --- You can also try to invert the nCS signal by your self and check what happens than :) --- Quote End --- Yea, I'm waiting to hear from MySupport. I'd try inverting but I use the same part for configuration. During configuration the sense of nCS is correct, it's after the FPGA enters user mode it gets hosed.
- Altera_Forum
Hello John,
A software bug report has been filed and we are all awaiting the solution. Your angel. - Altera_Forum
For closure: the megafunction did genrate code that inverted nCS in user mode and a smalll portion of megafunction code was required to be replaced. I'm told this will be fixed with Q8.
- Altera_Forum
Hi,
I have similar problem on Cyclone II EP2C5Q208C8N. Sometimes I can't read all EPCS configuration memory because it seams that nCS goes High from altasmi megafunction. Anybody has found a solution ? Ciao. Vittorio - Altera_Forum
The fix they gave me for Cyc III worked and they had promised me it'd be incorporated into Quartus 8; I haven't checked that yet though and probably won't until the next product update.
- Altera_Forum
Hi Johns,
what is the solution they gave you ? Vittorio
