Appendix A: Application Note; Ddr3 And Ddr4 Jedec Timing Violations Summary; V01 - Tras Activate To Precharge Command Period (Min); V02 - Tras Activate To Precharge Command Period (Max) - Teledyne Kibra DDR User Manual

Application Note
5.1

DDR3 and DDR4 JEDEC Timing Violations Summary

This Application Note summarizes the JEDEC timing violations for DDR3 and DDR4
currently supported in Teledyne LeCroy's Kibra 380 or Kibra 480 Protocol Analyzer. These
timing parameters are determined based on the CL, CWL, AL and operational timing mode
specified by the system memory controller and the SPD data in the DIMM.
5.1.1

V01 - tRAS ACTIVATE to PRECHARGE command period (Min)

The minimum interval between Activate and PreCharge is specified to ensure the active
row is closed before the next Activate or Refresh. This is the minimum amount of time
that must occur between activating a row and issuing a precharge to the row in same rank
and same bank. This makes sure that all the data from the row has been moved to the
sense amps and is stable before a precharge is issued to write the data back to the row.
Speed Grade
tRASmin (ns)
tRASmin (nCK)
5.1.2

V02 - tRAS ACTIVATE to PRECHARGE command period (Max)

The maximum interval between ACTIVATE and PRECHARGE to the same rank and same
bank is specified and is consistent with the Row to Row Delay (RRD). 9*tREFI is also the
maximum amount of time between refresh commands. As all Banks must be idle before
refresh, the maximum amount of time a Row can be active is the maximum amount of
time between refresh commands. This table is for Tcase = [0‐85°C].
Speed Grade
tRASmax (ns)
tRASmax (nCK)
Kibra DDR Protocol Analyzer User Manual
800 1066 1333
37.5 37.5 36
15 20 24
800 1066 1333
70200 70200 70200
28080 37416 46823
Appendix A
1600
35
28
1600
70200
56160