H5PS1G83EFR View Datasheet(PDF) - Hynix Semiconductor

Part Name

Description

Manufacturer

H5PS1G83EFR

1Gb DDR2 SDRAM

Hynix Semiconductor 

Release

H5PS1G83EFR Series

38 When the device is operated with input clock jitter, this parameter needs to be derated by { - tJIT(duty),max -

tERR(6-10per),max } and { - tJIT(duty),min - tERR(6-10per),min } of the actual input clock. (output deratings are rel-

ative to the SDRAM input clock.)

For example, if the measured jitter into a DDR2-1066 SDRAM has tERR(6-10per),min = - 202 ps, tERR(6-10per),max

= + 223 ps, tJIT(duty),min = - 66 ps and tJIT(duty),max = + 74 ps, then tAOF,min(derated) = tAOF,min + { -

tJIT(duty),max - tERR(6-10per),max } = - 350 ps + { - 74 ps - 223 ps} = - 647 ps and tAOF,max(derated) = tAOF,max

+ { - tJIT(duty),min - tERR(6-10per),min } = 950 ps + { 66 ps + 202 ps } = + 1218 ps. (Caution on the min/max

usage!)

39. For tAOFD of DDR2-1066, 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 tCK(avg). tAOF,min and tAOF,max 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. For example, if an input clock has a

worst case tCH(avg) of 0.48, the tAOF,min should be derated by subtracting 0.02 x tCK(avg) from it, whereas if an

input clock has a worst case tCH(avg) of 0.52, the tAOF,max should be derated by adding 0.02 x tCK(avg) to it. There-

fore, we have;

tAOF,min(derated) = tAC,min - [0.5 - Min(0.5, tCH(avg),min)] x tCK(avg)

tAOF,max(derated) = tAC,max + 0.6 + [Max(0.5, tCH(avg),max) - 0.5] x tCK(avg)

or

tAOF,min(derated) = Min(tAC,min, tAC,min - [0.5 - tCH(avg),min] x tCK(avg))

tAOF,max(derated) = 0.6 + Max(tAC,max, tAC,max + [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.

Note that 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;

tAOF,min(derated_final) = tAOF,min(derated) + { - tJIT(duty),max - tERR(6-10per),max }

tAOF,max(derated_final) = tAOF,max(derated) + { - tJIT(duty),min - tERR(6-10per),min }

Rev. 1.0 / Aug 2009

62

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