Hi Zheng, I believe that "-x GB" simply means that there are different Trfc values for each size module.
Trfc is stored in MTB units, though. So you need to: 1. Convert nCK to nanoseconds 2. Convert nanoseconds to MTB units
For example, if you have a 1Gb module that is running at 800MHz, then Trfc will be 88 clock cycles. 1sec / 800MHz = 1.25ns per cycle, therefore 88 cycles = 110ns.
Then you need to convert the total time into MTB units. So if your timebase (SPD bytes 10 and 11) is 0.125, Trfc is 110 / 0.125 = 880. (This matches the calculation shown for bytes 24 and 25 in the SPD spec: http://www.jedec.org/standards-documents/results/Annex%20K%20SPD).
On Fri, Apr 1, 2016 at 5:30 PM, Zheng Bao fishbaoz@hotmail.com wrote:
DDR3-1066 DDR3-1333 DDR3-1600 DDR3-1866unit 7-7-7 9-9-9 11-11-11 13-13-13 nRFC-1 Gb 59 74 88 103 nCK nRFC- 2 Gb 86 107 128 150 nCK nRFC- 4 Gb 160 200 240 281 nCK nRFC- 8 Gb 187 234 280 328 nCK
Hi, All, Above text is extracted from the spec of a DDR3 chip.
I am trying to decide the Trfc. What does "-x Gb" mean? How do I know which row in the table I should use? Thanks.
Zheng
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