k4h560838j Samsung Semiconductor, Inc., k4h560838j Datasheet - Page 18

• Manufacturer Part Number: k4h560838j
• Description: 256mb J-die Ddr Sdram Specification
• Manufacturer: Samsung Semiconductor, Inc.

21.0 Component Notes
10. The output timing reference voltage level is VTT.
11. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are not referenced to
12. The maximum limit for this parameter is not a device limit. The device will operate with a greater value for this parameter, but sys
13. The specific requirement is that DQS be valid (HIGH, LOW, or at some point on a valid transition) on or before this CK edge. A
14. A maximum of eight AUTO REFRESH commands can be posted to any given DDR SDRAM device.
15. For command/address input slew rate ≥ 1.0 V/ns
16. For command/address input slew rate ≥ 0.5 V/ns and < 1.0 V/ns
K4H560438J
K4H560838J
K4H561638J
1. All voltages referenced to Vss.
2. Tests for ac timing, IDD, and electrical, ac and dc characteristics, may be conducted at nominal reference/supply voltage levels,
3. Figure 1 represents the timing reference load used in defining the relevant timing parameters of the part. It is not intended to be
4. AC timing and IDD tests may use a VIL to VIH swing of up to 1.5 V in the test environment, but input timing is still referenced to
5. The ac and dc input level specifications are as defined in the SSTL_2 Standard (i.e., the receiver will effectively switch as a result
6. Inputs are not recognized as valid until VREF stabilizes. Exception: during the period before VREF stabilizes, CKE ≤ 0.2VDDQ is
7. Enables on.chip refresh and address counters.
8. IDD specifications are tested after the device is properly initialized.
9. The CK/CK input reference level (for timing referenced to CK/CK) is the point at which CK and CK cross; the input reference level
but the related specifications and device operation are guaranteed for the full voltage range specified.
either a precise representation of the typical system environment nor a depiction of the actual load presented by a production
tester. System designers will use IBIS or other simulation tools to correlate the timing reference load to a system environment.
Manufacturers will correlate to their production test conditions (generally a coaxial transmission line terminated at the tester elec-
tronics).
VREF (or to the crossing point for CK/CK), and parameter specifications are guaranteed for the specified ac input levels under nor-
mal use conditions. The minimum slew rate for the input signals is 1 V/ns in the range between VIL(ac) and VIH(ac).
of the signal crossing the ac input level and will remain in that state as long as the signal does not ring back above (below) the dc
input LOW (HIGH) level.
recognized as LOW.
for signals other than CK/CK, is VREF.
a specific voltage level but specify when the device output is no longer driving (HZ), or begins driving (LZ).
tem performance (bus turnaround) will degrade accordingly.
valid transition is defined as monotonic and meeting the input slew rate specifications of the device. when no writes were previ
ously in progress on the bus, DQS will be transitioning from High- Z to logic LOW. If a previous write was in progress, DQS could
be HIGH, LOW, or transitioning from HIGH to LOW at this time, depending on tDQSS.
Output
(Vout)
Figure 1 : Timing Reference Load
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VTT
50Ω
30pF
Rev. 1.0 September 2007
DDR SDRAM