ARM/DDR Clock speed for DM8148 EVM

Mohammad Kiaei

Greetings,

I noticed that the ARM and DDR clock rate of DM8148 EVM have been set to 600 Mhz and 400 Mhz, respectively. For DDR clock rate, there is a header file in EZSDK board-support folder, "ddr_defs_ti814x.h", where we can configure the registers for 400 MHz but not other speeds. I wonder how we can increase clock rates for ARM and DDR3 in order to handle 1080p-60 video streams at higher rates. For the EVM of DM8168, we were able to transmit and receive the 1080p-60 up to 25Mbps. But for DM8148 EVM, the received stream becomes corrupted even for 10mbps compressed streams.

Your comments are appreciated.

Regards,

Mohammad

over 13 years ago

0 Mohammad Kiaei over 13 years ago

Intellectual 675 points

I wonder if the clock speed of DDR and ARM has been limited in DM8148 SoC, or it is a limitation of the evaluation board. Please let me know your comments.

Thanks,

Mohammad

0 zhichao tan60372 over 12 years ago in reply to Mohammad Kiaei

Expert 1015 points

Hello Mohammad Kiaei:

Have you update the ARM/DDR Clock speed for DM8148 EVM?According to the followings infor from http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/241886.aspx)

to change the clocks you need to do 2 changes:

1. Update the domain rail voltage to appropriate voltage for the target OPP (1.1/1.2/1.35V). Target OPP depends on the final clock and again the device variant that you have.

2. Update the clock from u-boot. The logic for updating clocks can be referred in following file:

u-boot/arch/arm/include/asm/arch-ti81xx/clocks_ti814x.h

But how to change the OPP?In uboot or Kernel?Do you know?

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ARM/DDR Clock speed for DM8148 EVM