HY5PS12421CFP-E3 Datasheet, PDF (35/38 Pages) Hynix Semiconductor – 512Mb DDR2 SDRAM

1HY5PS12421C(L)FP
1HY5PS12821C(L)FP
1HY5PS121621C(L)FP
17. ODT turn off time min is when the device starts to turn off ODT resistance.
ODT turn off time max is when the bus is in high impedance. Both are measured from tAOFD.
18. tHZ and tLZ transitions occur in the same access time as valid data transitions. Thesed parameters are referenced
to a specific voltage level which specifies when the device output is no longer driving(tHZ), or begins driving (tLZ).
Below figure shows a method to calculate the point when device is no longer driving (tHZ), or begins driving (tLZ)
by measuring the signal at two different voltages. The actual voltage measurement points are not critical as long as
the calculation is consistenet.
19. tRPST end point and tRPRE begin point are not referenced to a specific voltage level but specify when the device
output is no longer driving (tRPST), or begins driving (tRPRE). Below figure shows a method to calculate these
points when the device is no longer driving (tRPST), or begins driving (tRPRE). Below Figure shows a method to
calculate these points when the device is no longer driving (tRPST), or begins driving (tRPRE) by measuring the
signal at two different voltages. The actual voltage measurement points are not critical as long as the calculation is
consistent.
tHZ
tRPST end point
VOH + xmV
VOH + 2xmV
VOL + 1xmV
VOL + 2xmV
VTT + 2xmV
VTT + xmV
VTT -xmV
VTT - 2xmV
tHZ
tRPRE begin point
tHZ , tRPST end point = 2*T1-T2
tLZ , tRPRE begin point = 2*T1-T2
20. Input waveform timing with differential data strobe enabled MR[bit10] =0, is referenced from the input signal
crossing at the V_IH(ac) level to the differential data strobe crosspoint for a rising signal, and from the input signal
crossing at the V_IL(ac) level to the differential data strobe crosspoint for a falling signal applied to the device under
test.
21. Input waveform timing with differential data strobe enabled MR[bit10]=0, is referenced from the input signal
crossing at the V_IH(dc) level to the differential data strobe crosspoint for a rising signal and V_IL(dc) to the
differential data strobe crosspoint for a falling signal applied to the device under test.
22. Input waveform timing is referencedDfrioffmertheenintipault sInigpnaul tcrwossainvgeaftotrhme Vt_IHim(aci)nlgevel for a rising signal and V_IL(ac) for a falling
signal applied to the device DunQdSer test.
23.
Input
waveform
timing
is referenced
DQS
from
the
input
signal
crossing
at
the
V_IL(dc)
level
for
a
rising
signal
and
V_IH(dc)
for
a
falling
signal applied to the device under test.
tDS tDH
tDS tDH
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
Rev. 0.8 / Oct. 2007
35