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I have a design I've built in QSYS using a 16-bit bus. I'd like to include the JTAG to Avalon Master in my design so that I can do a quick system-level check using TCL commands before handing it off to a software guy.
Before building this relatively complex design, I took a half a day to build and test a simple 8-bit design on an eval board. This is an incredible tool! However, I'm stuck getting the JTAG Master into my 16-bit design. QSYS complains that the JTAG master has an 8-bit symbol width, while all my slave devices have 16-bit widths. Is there a 16-bit version of the JTAG Master, or some "magic" 8-bit to 16-bit bridge I can put in? Thanks in advance!Link Copied
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The JTAG-to-Avalon-MM master has a 32-bit data bus. See Chapter 18
http://www.altera.com/literature/ug/ug_embedded_ip.pdf Under SOPC Builder you do not have any option to change the bus width. I assume that under Qsys its the same. The Qsys system builder should insert width adapters. If it does not, just create your own components with 32-bit widths, and generate two 16-bit transactions if all byte-enables are enabled. This is what I do to make 16-bit SRAM look like 32-bit SRAM. Cheers, Dave- Mark as New
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dwh -- That's puzzling, b/c QSYS gives the following error message
"Signal master[8] and signal avalon_slave_0[16] must have the same symbol width" I guess I could make the system 32-bit, but I'd prefer to figure out what's going on here. I thought that the bus width was automatically handled under QSYS. I'm just using QSYS to connect the bus fabric and for the JTAG debug capability. The FPGA attaches externally to a separate DSP.- Mark as New
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--- Quote Start --- That's puzzling, b/c QSYS gives the following error message "Signal master[8] and signal avalon_slave_0[16] must have the same symbol width" --- Quote End --- That sounds like a how many bits per byte issue. Look in the _hw.tcl file for your component and see if you have a 16-bit symbol size, rather than 8-bit symbol size. --- Quote Start --- I guess I could make the system 32-bit, but I'd prefer to figure out what's going on here. I thought that the bus width was automatically handled under QSYS. I'm just using QSYS to connect the bus fabric and for the JTAG debug capability. The FPGA attaches externally to a separate DSP. --- Quote End --- The JTAG-to-Avalon-MM master, and SignaTap II are very useful for debugging problems, so its definitely worth figuring out what is wrong. Cheers, Dave
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Dave -- Thanks. It was a symbol width mismatch. I had not understood why Altera was asking for the symbol size and had defined the 16-bit bus width parts as having 16-bits per symbol. Now I also understand the addressing increments as well. This is great.
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--- Quote Start --- It was a symbol width mismatch. I had not understood why Altera was asking for the symbol size and had defined the 16-bit bus width parts as having 16-bits per symbol. Now I also understand the addressing increments as well. --- Quote End --- Great! Now you can move onto your next problem :) Cheers, Dave
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