Hi,I got TMS570LS31x Hercules Development Kit, and want to use the external 8MB SDRAM.But, it seems that I can't access SDRAM.Is there any initialization step to use SDRAM?
I made TMDX570LS31HDK project by HALCoGen(2.09.001) and "Generate Code" default settings.I added some callback funcs and build projects CCS(4.2.5.00005).In main func, I added the following codes to check access to SDRAM. volatile int *p = (volatile int*)0x80000010; int tmp0, tmp1, tmp2; void main(void) { tmp0 = *p; *p = 1234; tmp1 = *p; *p = 5678; tmp2 = *p; }I watched tmp0,tmp1,tmp2 by debugger, but these values '0' (sometimes'-1409474866').I checked HALCoGen settings. - Mpu setting Region 6 Configuration is checked 'Enable Mpu Region' Base Address : 0x80000000 Size : 128_MB End Address : 0x87ffffff no check Disable Sub-Region 0 to 7 Type : STRONGLYORDERD_SHAREABLE Permission : PRIV_RW_USER_RW_EXEC - No EMIF setting tabWhat can I do to access SDRAM?Please help me!
Takashi,
The SDRAM on the HDK is accessible via the EMIF Module.
There is another thread on the forum with an example at the following link
http://e2e.ti.com/support/microcontrollers/hercules/f/766/t/180728.aspx
Please have a look and let me know.
Regards,
Jean-Marc
Best regards,
Application Engineer
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Jean-Marc,Thank you very much for your advice.I did following things and I can read/write CS0 space now. - updated HACCoGen(3.00.01), I found EMIF tab - set same parameters as sample code(7215.EMIF.zip) - select "PINMUX" tab and check EMIF boxRegards,ttaka.P.S.I measured access time, EXT-SDRAM was 10 times slower than internal RAM.Is this a reasonable result?Should I change the EMIF parameters?
Hello,
The speeds you are seeing are within expected range of performance. This device is not optimized for performance with external memory, but the internal SRAM performance is highly optimized.
Karl
Karl,Thank you for your reply.Hmm.The internal SRAM may be not enough for our planning equipment.We must tune up memory allocation.Regards,ttaka.