Hi,
I'm currently working on the DSP (HiFi 4) of a RT685 Audio EVK. I would like to know the HEAP size on that DSP and how to change that value.
Thank you.
Hi @AleP ,
Please check the build properties:
elf32xtensa.x,memmap.xmm
path:SDK_2_13_0_EVK-MIMXRT685\devices\MIMXRT685S\xtensa\gdbio\ldscripts
Wish it helps you!
Best Regards,
Kerry
Hi,
My device, from the datasheet, has 4.5 MB of RAM, but 0x480000 (the value I've found in my project) is actually 4.5 MB. How is that possible? Where is the stack then if all the memory is HEAP?
This is my configuration (default):
BEGIN dsp_core
0x00200000: sysram : dsp_core : 0x280000 : executable, writable ;
dsp_core : C : 0x00200000 - 0x0047ffff : STACK : HEAP : .rodata .literal .text .data __llvm_prf_names .bss;
END dsp_core
BEGIN dsp_uncached
0x20000000: sysram : dsp_uncached : 0x480000 : uncached, executable, writable ;
dsp_uncached : C : 0x20060000 - 0x2006ffff : NonCacheable.init NonCacheable ;
END dsp_uncached
BEGIN dram0
0x24000000: dataRam : dram0 : 0x10000 : writable ;
dram0_0 : C : 0x24000000 - 0x2400ffff : .dram0.rodata .ResetVector.literal .Level2InterruptVector.literal .Level3InterruptVector.literal .DebugExceptionVector.literal .NMIExceptionVector.literal .KernelExceptionVector.literal .UserExceptionVector.literal .DoubleExceptionVector.literal .iram0.literal .dram0.data .dram0.bss;
END dram0
Best regards,
Alessandro
Hi @AleP ,
I find the SDK doc Getting Started with Xplorer for EVK-MIMXRT685.pdf already mention the stack and heap situation:
So, the 0x00480000 is the entrypoint, it it the top of the segment, and count top down, so, in fact, the size also from 0x00480000.
Please check the doc on your side.
Wish it helps you!
Best Regards,
Kerry
Hi,
Thank you for your feedback. The board should have 64 MB of RAM:
Board Memory
- 64MB Macronix MX25U51245GXDI00 quad SPI flash
- 64MB AP Memory APS6408L-OBM-BA PSRAM
Is therefore possible to expand the RAM available to the DSP? 2.5 MB sometimes is not enough.
If it's possible, do I have to change only the 48 0000 value? Do I have to change it in all the files that are visible in your screenshot?
Thank you for your support.
Best regards,
Alessandrp
Hi @AleP ,
If you expand the RAM side, do you want to use the external RAM chip?
Best Regards,
Kerry
Hi,
Yes, if it's possible it would be very useful.
Thank you.
Best regards,
Alessandro
Hi @AleP ,
As I know, the RT685 can expand the RAM with the flexSPI, you can check the SDK code:
SDK_2_13_0_EVK-MIMXRT685\boards\evkmimxrt685\driver_examples\flexspi\psram
It is using the external PSRAM with the flexSPI interface.
Wish it helps you!
Best Regards,
Kerry
Hi @AleP ,
Please keep patient, let me double check it internally, then I will give you the updated information.
Best Regards,
Kerry