Hello,
I changed the values for PLL in the startup_RTX.s file from the "HTTP_Example with RTX". Following is the code I changed. The original values are the one with ";" in front. This part of coude can be found at around line 300 of the startup file.
;PLLCFG_Val EQU 0x00000007 ;7+1 = 8 * multiplier van mainclock (=>72MHz) PLLCFG_Val EQU 0x0000000B ;11+1 = 12 * (12*2)/1 = 288MHz intern ;CCLKCFG_Val EQU 0x00000003 ;3+1 = 4 * divider van PLLclock CCLKCFG_Val EQU 0x00000004 ;3+1 = 4 * divider van PLLclock = 72MHz ;USBCLKCFG_Val EQU 0x00000003 ;3+1 = 4 * divider van PLLclock USBCLKCFG_Val EQU 0x00000005 ;5+1 = 6 * divider van PLLclock = 48 MHz PCLKSEL0_Val EQU 0x00010000 ;PCLK_SPI set to CCLK (48MHz)
So I changed it to have the following things: -internal PLL rate of 288MHz -divided by 4, this gives 72MHz for CPU -divided by 6, this gives 48MHz for USB
When I do this, then the system clock isn't correct any more. What do I have to change to get it right again? The original CPU speed is 48MHz. So when I want to generate a periodic cycle of 2s, it's now only 1.333s...
Also, could it be that the CPU is less stable? When I reset my CPU, it blocks about 4 on 5 times.
Anyone got any experience with this?
When I fill in this one, I get the same values as the one I calculated. M value = 12, N value = 1
But in this app you can only have CPU speed of 48MHz if I choose USB. But it must be possible to choose a CPU speed wich is not depending on the one of USB (at least I think so)
Do I have to change something in the RTX_Config file when I change these timings?