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 <fishb...@hotmail.com> wrote: > DDR3-1066 DDR3-1333 DDR3-1600 DDR3-1866 > unit > 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 > > -- > coreboot mailing list: coreboot@coreboot.org > https://www.coreboot.org/mailman/listinfo/coreboot >
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