AM3352: When the CPU transfers data from USB FIFO to DDR2, the speed becomes very slow.

Part Number:AM3352

Hi everyone, 

When the CPU transfers data from USB FIFO to DDR2, the speed becomes very slow.

• When reading and discarding the data of USB FIFO by CPU, it is 15 ~ 19MB / s.
• When transferring data from USB FIFO to DDR2 by CPU, it is 1.5 ~ 1.6MB / s.

I would like to know why data transfer to DDR would slow down to 1/10 this way.
The PLL sets L3F_CLK to 200 MHz and L2S_CLK to 100 MHz.

Best regards,

Sasaki