keith
This is exactly the problem that I’ve been facing for the last couple weeks. I could get the memory tests to pass at 100% if only the CPU was talking with the external SRAM. As soon as I added in my time slot...
SRAM Frame Buffer is now up and running!
Exciting times for the Hope Badge Computer. Tonight, I’ve worked out most of the kinks with interfacing the new SRAM module which you can see in posts below this, to the J68 soft-core CPU. This means that I can...
SRAM PCB built, populated, and is testing good!
The circuit board arrived from Elecrow PCB in China, and it works without modification! My friend Brian from Canada helped me out again, laying out this PCB in short order. He did a great job! Soldering the half-mm...
New SRAM PCB is being built
So up to two SRAMs can be installed on this tiny 2″ x 2″ board. To the right is the connector, and the SRAMs are on the left. With current SRAM sizes, you can install 32-megabit SRAMs. That’s 4...
J68 can now speak with BEMICRO MAX 10 onboard SDRAM
So for the longest time, I’ve wanted to use the onboard 8MB SDRAM that is present on the BEMICRO MAX 10 fpga eval board. This is now a reality! I’ve successfully integrated a controller with some glue logic...
Modified memory controller now functioning on BEMICRO MAX 10 board
So after some minor heartache, I’ve managed to get a working memory controller on the BEMICRO Max 10 board that is easy to use. It uses a wishbone interface. The heart of the controller is from here but there were...
Something old, something new: building a NAS with a few older parts
About eight years ago, I bought a Dell XPS 420 pictured above. This was an Intel Core 2 Quad Q9550 running at 2.83ghz. With 8GB of ram. Despite running reliably for over 8 years, the main problem was that the case was a...
New project: modifying Logitech C920 webcam for PCB inspection
I’ve recently spent some time modifying a Logitech C920 webcam for PCB inspection and soldering. Head over to the page for project pictures, links to the various components, tricky gotchas I found during...
Memory controller work continues….workaround 4MB SRAM add-on
SO here’s a couple hundred dollars of SRAM parts ordered to add on to the FPGA. It goes like this: the memory controller isn’t fully integrated yet into the J68 soft-core, so I’ve decided to whack on 4...
Cirrus Logic CS4335 DAC problems finally identified and fixed.
I had some assistance in fixing this problem. My always helpful friend Brian from Canada as well as some help from Steve @ the Audacity forums contributed to solving the problem. They filled in some blanks for me, and...
left-justified DAC problems continue
Here you see the analog sound waveform coming out of the DAC at the top in yellow. I think I’m getting closer……I switched from the I2S DAC to a left-justified DAC just because the LJ one is a little...
Trying to debug my design for an Audio DAC Cirrus Logic CS4334
I purchased a CS4334 to eventually use as an Audio DAC for the badge computer. I’ve never worked with DACs before, and my knowledge of audio is somewhat limited. This audio DAC is a Cirrus Logic CS4334 with...
J68 is now booting from User Flash Memory on the BEMICRO MAX10 FPGA board
I’ve been struggling for quite a few nights and weekends over the last month or so. I’ve now successfully attached the J68 to the built-in User Flash Memory. This means that the 16KB (actually about ~13KB)...
Still debugging the attachment of User Flash Memory to the J68….
So if I take my working UFM avalon-mm Master controller (which if you recall, connects to the Altera Flash Memory IP core), and attempt to attach it to the J68, the J68 no longer boots the ROM monitor code. Since...
LCD Test image and pixel-level detail
So I’ve managed to get a semi-working test pattern image up on the LCD. Here are a couple shots: If we zoom in about 10 times, we can see how the LCD really works, on an individual pixel level: Pretty challenging...
Reverse engineering the LCD interface
So I was having trouble getting the LCD working initially, so I ended up probing a working HDMI to LCD converter board sold by adafruit. You see, this board was driving my LCD just fine, but my FPGA couldn’t do...
J68 boots VUBUG monitor on the BEMICRO MAX 10 FPGA board
Here’s an image showing a ROM monitor VUBUG running on the J68 softcore, which is in turn running on a BEMICRO Max 10 FPGA board.
VUBUG will be used until we can get our own (unwritten, so far) custom code booting!
Working on the User Flash Memory
So the Altera Max 10 FPGA we’re using has 256kbits of User Flash Memory. This is non-volatile memory that is built into the actual FPGA itself. This means you don’t need any external memory to get the FPGA...
