AS4C128M16D3B Datasheet, PDF (33/41 Pages) Alliance Semiconductor Corporation – 2Gb AS4C128M16D3B-12BCN - 96 ball FBGA PACKAGE

AS4C128M16D3B-12BCN
Speed Bin Table Notes
NOTE :
1. The CL setting and CWL setting result in tCK(avg) Min and tCK(avg) Max requirements. When making a selection
of tCK(avg), both need to be fulfilled: Requirements from CL setting as well as requirements from CWL setting.
2. tCK(avg) Min limits: Since CAS Latency is not purely analog - data and strobe output are synchronized by the DLL -
all possible intermediate frequencies may not be guaranteed. An application should use the next smaller JEDEC
standard tCK(avg) value (2.5, 1.875, 1.5, or 1.25 ns) when calculating CL [nCK] = tAA [ns] / tCK(avg) [ns], rounding
up to the next "Supported CL".
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. 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. .
6. _{tREFI depends on operating case temperature (Tc).}
7. For devices supporting optional downshift to CL=7 and CL=9, tAA/tRCD/tRP min must be 13.125 ns or lower. SPD
settings must be programmed to match. For example, DDR3-1600(CL11) devices supporting downshift to
DDR3-1333(CL9) or DDR3-1066(CL7) should program 13.125 ns in SPD bytes for tAAmin (Byte16), tRCDmin (Byte
18), and tRPmin (Byte 20). DDR3-1600 devices supporting down binning to DDR3-1333 or DDR3-1066 should
program 13.125ns in SPD byte 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 accodingly.For example, 49.125ns,
(tRASmin + tRPmin = 36ns + 13.125ns) for DDR3-1333 and 48.125ns (tRASmin + tRPmin = 35ns + 13.125ns) for
DDR3-1600.
Confidential
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Rev.1.0 Mar. 2016