Mikromedia dspic33EP DMA

[jmusselman64]

Does the Mikrobasic dspic224/33 compiler support dma for the mikromedia dspic33EP board?

I'm beginning work on another section of code that will use DMA and the TX side of a UART, so I'm setting up a buffer with:

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dim testbuffer as byte[32] dma

just to make sure the compiler is happy...and it isn't:

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1 1015 Hint: Compiling unit "H:\Documents\Programming-JAM\BASIC\MikroBasic24\Projects\AR5_V3\AR5_V3_main.mbas" AR5_V3_main.mbas
162 1010 Hint: Unit "AR5_V3_main.mbas" has been recompiled AR5_V3_main.mbas
0 134 Compiled Successfully H:\Documents\Programming-JAM\BASIC\MikroBasic24\Projects\AR5_V3\AR5_V3_main.mbas
0 139 All files Compiled in 47 ms  
76 362 Not enough RAM 'testbuffer' AR5_V3_main.mbas
0 453 Unsuccessful linking 'AR5_V3.mbpds' Unsuccessful linking 'AR5_V3.mbpds'
0 102 Finished (with errors): 05 Sep 2018, 07:01:12 AR5_V3.mbpds

The .def file seems like it has the correct info regarding DMA memory..am I missing something?

Thanks,
Jerry

[filip]

Hi,

Try this :

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dim testbuffer as byte[32] dma far

Regards,
Filip

[jmusselman64]

The DMA RAM section of the compiler appears to have a bug
The following test code reserves a simple DMA buffer in DMA RAM.

On the DSPIC33EP512MU810, DMA ram is from 0x00E000 - 0x00DFFF

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program asmtest
'  Processor : DSPIC33EP512MU810

' Declarations section 

dim testbuffer as word[16] dma far
dim testbuff_addr as longword

main:
'   Main program 
testbuff_addr =  @testbuffer

DMA0STAL = loword(testbuff_addr)
DMA0STAH = hiword(testbuff_addr)

while (1)
wend

end.

The variable 'testbuff_addr' ends up outside the chips RAM space at at 0x01DFE0 . It should be 0x00DFE0.

[petar.suknjaja]

Hi,
We'll investigate this and I'll let you know if I find something new.
Kind regards,
Petar