Hynix HMT351U7CFR8A-PBT0 Benutzerhandbuch

Absolute Specification (T

OPER

; V

DDQ

 = V

DD

 = 1.35V +0.100/- 0.067 V); 

1. The CL setting and CWL setting result in tCK(AVG).MIN and tCK(AVG).MAX requirements. When mak-

ing a selection of tCK(AVG), both need to be fulfilled: Requirements from CL setting as well as require-

ments from CWL setting.

2. tCK(AVG).MIN limits: Since CAS Latency is not purely analog - data and strobe output are synchro-

nized by the DLL - all possible intermediate frequencies may not be guaranteed. An application should 

use the next smaller JEDEC standard tCK(AVG) value (3.0, 2.5, 1.875, 1.5, or 1.25 ns) when calculat-

ing CL [nCK] = tAA [ns] / tCK(AVG) [ns], rounding up to the next ‘Supported CL’, where tCK(AVG) = 

3.0 ns should only be used for CL = 5 calculation.

3. tCK(AVG).MAX limits: Calculate tCK(AVG) = tAA.MAX / CL SELECTED and round the resulting tCK(AVG) 

down to the next valid speed bin (i.e. 3.3ns or 2.5ns or 1.875 ns or 1.25 ns). This result is 

tCK(AVG).MAX corresponding to CL SELECTED.

4. ‘Reserved’ settings are not allowed. User must program a different value.
5. ‘Optional’ settings allow certain devices in the industry to support this setting, however, it is not a man-

datory feature. Refer to DIMM data sheet and/or the DIMM SPD information if and how this setting is 

supported.

6. Any DDR3-1066 speed bin also supports functional operation at lower frequencies as shown in the 

table which are not subject to Production Tests but verified by Design/Characterization.

7. Any DDR3-1333 speed bin also supports functional operation at lower frequencies as shown in the 

table which are not subject to Production Tests but verified by Design/Characterization.

8. Any DDR3-1600 speed bin also supports functional operation at lower frequencies as shown in the 

table which are not subject to Production Tests but verified by Design/Characterization. 

9. DDR3 SDRAM devices supporting optional down binning to CL=7 and CL=9, and tAA/tRCD/tRP must be 13.125 ns 

or lower. SPD settings must be programmed to match. For example, DDR3-1333H devices supporting down bin-
ning to DDR3-1066F should program 13.125 ns in SPD bytes for tAAmin (Byte 16), tRCDmin (Byte 18), and tRP-
min (Byte 20). DDR3-1600K devices supporting down binning to DDR3-1333H or DDR3-1600F should program 
13.125 ns in SPD bytes for tAAmin (Byte 16), tRCDmin (Byte 18), and tRPmin (Byte 20). Once tRP (Byte 20) is 
programmed to 13.125ns, tRCmin (Byte 21,23) also should be programmed accordingly. For example, 49.125ns 
(tRASmin + tRPmin = 36 ns + 13.125 ns) for DDR3-1333H and 48.125ns (tRASmin + tRPmin = 35 ns + 13.125 
ns) for DDR3-1600K.