We are using LS1043A in our System. I need to Set the RCW configuration for MEM_PLL_RAT(10-15)

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We are using LS1043A in our System. I need to Set the RCW configuration for MEM_PLL_RAT(10-15)

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logeshs
Contributor II

I have doubt in setting RCW  value for bits MEM_PLL_RAT(10-15) which is used to select DDR Clock. In datasheet in table 159 it is mentioned as the ratio  between DDR datarate: DDRCLK ratio, but in Reference Manual It is mentioned as the ratio between DDR PLL:SYSCLK Ratio. 

 

My Core Freq is 1.6GHz, Platform Freq is 400MHz, and DDR Data rate need to 1600MT/s. Kindly help me what value should i keep in MEM_PLL_RAT(10-15) RCW setting?

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logeshs
Contributor II

I'm clear that it can be supplied with either DDRCLK or DIFF_SYSCLK/DIFF_SYSCLK_B, but the doubt is whether to consider Reference Manual or the Datasheet for selecting DDR PLL Clock frequency. 

I need DDR datarate of 1600MT/s, My SYSCLK freq is 66.67MHz and DDRCLK input is 66.67MHz (Both are Single Ended Input). Kindly suggest me the Ratio Value for the MEM_PLL_RAT.

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ufedor
NXP Employee
NXP Employee

Rate=1600/66.7=24

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367 Views
logeshs
Contributor II

Thank you.

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367 Views
ufedor
NXP Employee
NXP Employee

Either DDRCLK or DIFF_SYSCLK/DIFF_SYSCLK_B could be used as DDR PLL clock - please refer to the QorIQ LS1043A Reference Manual, Table 4-14. RCW Field Descriptions.

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