K4T1G044QF SAMSUNG [Samsung semiconductor], K4T1G044QF Datasheet - Page 46

• Manufacturer Part Number: K4T1G044QF
• Description: 1Gb F-die DDR2 SDRAM
• Manufacturer: SAMSUNG [Samsung semiconductor]

K4T1G044QF
K4T1G084QF
K4T1G164QF
44. For tAOFD of DDR2-400/533, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH, input clock HIGH pulse width of 0.5 relative to tCK. tAOF,min and
45. For tAOFD of DDR2-667/800, the 1/2 clock of nCK in the 2.5 x nCK assumes a tCH(avg), average input clock HIGH pulse width of 0.5 relative to
For example, if an input clock has a worst case tCH of 0.45, the tAOFmin should be derated by subtracting 0.05 x tCK from it, whereas if an input clock
For example, if an input clock has a worst case tCH(avg) of 0.48, the tAOFmin should be derated by subtracting 0.02 x tCK(avg) from it, whereas if an
NOTE : Tthat these deratings are in addition to the tAOF derating per input clock jitter, i.e. tJIT(duty) and tERR(6-10per). However tAC values used in the equations shown
above are from the timing parameter table and are not derated. Thus the final derated values for tAOF are;
tAOFmin(derated_final) = tAOFmin(derated) + { - tJIT(duty)max - tERR(6-10per)max }
tAOFmax(derated_final) = tAOFmax(derated) + { - tJIT(duty)min - tERR(6-10per)min }
tAOF,max should each be derated by the same amount as the actual amount of tCH offset present at the DRAM input with respect to 0.5.
has a worst case tCH of 0.55, the tAOFmax should be derated by adding 0.05 x tCK to it. Therefore, we have;
tCK(avg). tAOFmin and tAOFmax should each be derated by the same amount as the actual amount of tCH(avg) offset present at the DRAM input
with respect to 0.5.
input clock has a worst case tCH(avg) of 0.52, the tAOFmax should be derated by adding 0.02 x tCK(avg) to it. Therefore, we have;
tAOFmin(derated) = tAC,min - [0.5 - Min(0.5, tCHmin)] x tCK
tAOFmax(derated) = tAC,max + 0.6 + [Max(0.5, tCHmax) - 0.5] x tCK
or
tAOFmin(derated) = Min(tACmin, tACmin - [0.5 - tCHmin] x tCK)
tAOFmax(derated) = 0.6 + Max(tACmax, tACmax + [tCHmax - 0.5] x tCK)
where tCHmin and tCHmax are the minimum and maximum of tCH actually measured at the DRAM input balls.
tAOFmin(derated) = tACmin - [0.5 - Min(0.5, tCH(avg)min)] x tCK(avg)
tAOFmax(derated) = tACmax + 0.6 + [Max(0.5, tCH(avg)max) - 0.5] x tCK(avg)
tAOFmin(derated) = Min(tACmin, tACmin - [0.5 - tCH(avg)min] x tCK(avg))
tAOFmax(derated) = 0.6 + Max(tACmax, tACmax + [tCH(avg)max - 0.5] x tCK(avg))
where tCH(avg),min and tCH(avg),max are the minimum and maximum of tCH(avg) actually measured at the DRAM input balls.
datasheet
- 46 -
DDR2 SDRAM
Rev. 1.11