DDR speed specification clarification.

[toddreed]

Hi,

The DDR Speed specification in the part number is the maximum transfers per second, correct?  And there is no link between the max spec and the speed you run?  So I could use an "F=667MHz" part and run it at a 200Mhz clocking rate with 400MT/s?

Thank you,

Todd

[r8070z]

Have a great day,

Yes the DDR Speed specification in the part number is the maximum transfers per second. I.e. maximum DDR controller clock is 667/2MHz for the "F=667 MHz" part. Minimal frequency can be limited by the system PLL or DDR PLL. It should be checked in the documentation for particular device. Typically 200 MHz DDR memory clock can be used but only for the QorIQ devices which support DDR2 memory. The DDR3 standard increases the minimum clock frequency to 300 MHz.

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