if i change my ddr2 freq from 162MHZ to 135Mhz in dm6437,what other works i need to do ?

Junfeng Chen

Prodigy 130 points

hello everyone,

in my board of dm6437, i changed my ddr2 freq from 162MHZ to 135MHZ, and the default freq of evm board is 162MHZ,

in this case ,if i change the gel file ,i can connect to my board through xds560 emulation,

but the question is , do i need to change other files or functions to ensure my project is right ?

for example, the code below may need to be changed.

the function of EVMDM6437_init() my have some problem .

/*---------------------------------------------------------------------------------------------------------------------------------------------

void dm6437_init()

{

// Init the board

EVMDM6437_init();

// Read the MAC Address from EEPROM

EVMDM6437_EEPROM_read (0x00007F00, (Uint32) bMacAddr, 8);

}

*/---------------------------------------------------------------------------------------------------------------------------------------------

over 14 years ago

0 Paul.Yin over 14 years ago

TI__Genius 14405 points

Hi,

I fail to see why the code you inserted needs to be changed. What project are you referring to? is it something that TI provides?

If all you changed is the DDR frequency, all you need should be updating the DDR initialization function in the GEL file.

0 Davy over 14 years ago in reply to Paul.Yin

Prodigy 120 points

You will have to modify the DDR settings & PLL code to change the clock rate, else it'll revert back to the default 162 MHz. This is in the BSP code when EVMDM6437_init() is called.

Your code does not need to change when modifying the DDR settings.

0 Junfeng Chen over 14 years ago in reply to Davy

Prodigy 130 points

i need to modify the evmdm6437_ddr.c in evmdm6437bsl project.

then build a new library which is called evmdm6437bsl .lib.

0 Davy over 14 years ago in reply to Junfeng Chen

Prodigy 120 points

Yes. Change EVMDM6437_DDR_init() to modify the freq, then in EVMDM6437_startupGEL() change the EVMDM6437_enablePll2( ); settings to support DDR2 @ 135 MHz.

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if i change my ddr2 freq from 162MHZ to 135Mhz in dm6437,what other works i need to do ?