Arduino for STM32

Hi Gonzo, Yes, unrolling the loop probably gives better performance, still, I am not convinced *exactly where* the bottleneck is, I believe the AHB bus is running at 240 Mhz, however I am not sure the GPIO clock is at that level, and the AT32F403A *is* different in the clock tree (vs STM32XXX). I am...

Hmmm,

In the AT32F403A GPIO(A-E) are not located on a APB bus, but stuck directly onto the AHB. The AHB is clocked at 240 Mhz. (not divided)
So, question becomes more interesting.....

GPIO clock is 120 Mhz if I understand the setup. That would be a period of 8.33 nS.
And publishing square bracket left index square bracket right semicolon drops the index on preview or publish
using an index i does not work, but index k does work
left is index i, right is index k [k]

i did write
.....= datarray; but the index disappeared....

Thanks guys, I am now using this little loop for testing. // write alternate all zeros and all ones into datarray so I can scope on all pins. for(k=0;k<maxdata;k++) { if(( k & 1) == 0) datarray[k] = 0x0; else datarray[k] = 0xffff; } t1 = millis(); for(i=0;i<maxdata;i++) { // datarray[i] = (*(uin...

I have made a small sketch that just sends the contents of an array to PORTB. This indicates about 2 Mhz toggling. the code is extremely simple, just for (i=0;i<maxarray;i++) { GPIOB = maxarray ; } Why so slow? How do I display the generated assembly code? I am running the CPU at 240 Mhz. 240/2 , 12...

Trying a small sketch I found GPIOB not being enabled. Dumping the CRM_APB2 register shows no clock at GPIOB. I enabled that oring 0x8 to the register, and the port gives reasonable values. The reason for A and C being already enabled is of course the use of PC13 for the led and PA9-PA10 for serial....

Hi, Some progress, DFU upload did not work until I edited /etc/udev/rules.d/50-usb-conf.rules SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="df11", GROUP="users", MODE="0666" SUBSYSTEMS=="usb", ATTRS{idVendor}=="2e3c&qu...

It seems F_CPU is NOT calculated, but is a constant of 80.000.000.....

Reading the CRM_CFG register, the PLL mult factor should be the input parameter...

Gullik

Ok, now I can compile and download code. Unfortunately I seem to have destroyed the DFU uploader, and I cannot get it properly installed with the current json. With the above described procedure, and editing the platform.txt and boards.txt and replacing all \ with / in file paths it is now possible ...