AnsweredAssumed Answered

Unmatch about DDR DDR Output Driver Average Impedance for i.MX53

Question asked by ko-hey on Aug 7, 2018
Latest reply on Sep 10, 2018 by TomE
  • Comment • 2

Hi all

 

I have questions about DDR calibration resistance in Output Driver Average Impedance for i.MX53.

 

As it mentioned in following thread, the Table 43-2 and 43.3.454 unmatched and we have same question.

But there didn't answer the thread.

https://community.nxp.com/thread/328744

 

Q1.

Table 43-2 does not describe the DSE value when it set DDR3 dde_sel = 01.

Refer to 43.3.454 IOMUXC_SW_PAD_CTL_GRP_DDR_TYPE and it is explained as "NVCC_EMI_DRAM = 1.5 V +/- 5% (DDR 3), ddr_sel = '' 01: 160 Ohm '

 

In the case of dde_sel = 01 setting of DDR3, is the value of DSE the same as DDR_SEL = 01/11 of LPDDR 2 mode in Table 43-2 ?

 

Q2.

If Q1 is not same, could you provide a DSE value when it set DDR3 dde_sel = 01 ?

 

Q3.

We think that the calibration resistance which is shows in yellow line is wrong.

Because there are no settings in Table 43.3.454.

 

The correct calibration resistance is 200 Ohm. Am I correct ?

 

 

 

Ko-hey

igorpadykov
igorpadykov Employee Aug 8, 2018 4:17 PM
Correct Answer

Hi Ko-hey

 

>Q1.2

 

please refer to below description

 

 

>Q3

 

correct is 240 Ohm

 

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

See the reply in context
No one else had this question

Outcomes