Search found 81 matches

by mast3rbug
Thu Mar 07, 2019 1:20 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

I understand the Global Idea, but you still have to construct all that on the top of a precise timed Audio/Video frame. This is exactly the same as my Videogame console on my atXmega and the one I'm building on the ARM. the two are "kind of" complatible by software source code. Only the speed and so...
by mast3rbug
Wed Mar 06, 2019 4:38 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

It looks a pretty challenge if you take into account that making a stable picture on only one Micro is already tricky. How will you code all the kernels for all the differents Microcontrollers? You will have to purchase a lot of development kits and debuggers to achieve this. You also have to write ...
by mast3rbug
Sun Feb 24, 2019 10:45 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

Thanks for All that information, It help me to understand better some points in how cache works. I made a small cool effect yesterday, my goal with this Microcontroller is maybe made a demoscene with it like Amiga style. So I started made my first cool effect. Not too bad for a first one. I use no s...
by mast3rbug
Sat Feb 23, 2019 10:37 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

interesting experiment, Just be "Enabling" Cache in the main program and "Disabling it" in the Video Interrupt Accelerate the frame rate 2.5 X faster. Also, when doing smoot code in the Main Loop (I mean, not too much calculation like the VRML object but only LOOPS to move Memory Data on the screen)...
by mast3rbug
Fri Feb 22, 2019 10:53 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

Alittle interesting test I made just out of curiosity, I wanted to know the difference in rendering Between Atxmega and ARM, I made two small videos of VRML object rendering; In Red: Cortex M4 120 MHZ (SAMD51G19A). In Green: Atxmega 256 A3. 32 MHZ overclocked to 48 MHZ. The line routine is in C, I n...
by mast3rbug
Tue Feb 19, 2019 11:33 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

By the way for some tricks on setting up stuff on an ARM, you may check the BitBox repo, it is mostly done at bare metal level, although for an STM32F4. But some ideas could be useful for approaching the problem. I looked at the bitbox console, it have a really good hardware, I may be wrong but the...
by mast3rbug
Sun Feb 17, 2019 10:40 pm
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

DMA has to be able to be slowed down. Otherwise it would be useless for comminications things that are slower than the CPU clock. Look in the datasheet for "conditional transfer on strobe" You should be able to make a timer produce a 25.17Mhz tick from a 100.68 Mhz main clock for this. Also the HSB...
by mast3rbug
Sun Feb 17, 2019 11:58 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

VGA (640x480) timing is 800 total clocks per line at 25Mhz. Have you considered just DMAing 800 bytes to the port in an endless loop and having the timers make the syncs. Just leave the first 112 and the last 48 bytes zero and only write to the middle 640. Or you could waste 1600 bytes and ping-pon...
by mast3rbug
Sun Feb 17, 2019 9:54 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

Is the code halfword aligned (2 byte alignment)? It may happen that it isn't, then that would be a problem. I made .align 4 just before the function, followed by the .thumb_func (like all the other ASM function in the others flash code, if not, it also crash in the Handler interrupt) Let me know if...
by mast3rbug
Sun Feb 17, 2019 8:31 am
Forum: Uzebox Derivatives & open source consoles
Topic: Experimentation with Adafruit ItsyBitsy M4 board
Replies: 31
Views: 5332

Re: Experimentation with Adafruit ItsyBitsy M4 board

Thanks for the information.

Today, I tried to put some Assembly code in RAM with .data section. It crashed automatically at the first instruction to the dummy handler interrupt. DO you know what I missed here? What is the proper way to put code in RAM?

Cedric