IC42S32400 Datasheet, PDF (15/62 Pages) Integrated Circuit Solution Inc – 1M x 32 Bit x 4 Banks (128-MBIT) SDRAM

IC42S32400
IC42S32400L
7 Mode Register Set command
(RAS#=”L”,CAS#=”L”,WE#=”L”,BS0,1 and A11-A0 =Register Data)
The mode register stores the data for controlling the various operating modes of SDRAM.The Mode Register Set
command programs the values of CAS#latency,Addressing Mode and Burst Length in the Mode register to make
SDRAM useful for a variety of different applications.The default values of the Mode Register after power-up are
undefined;therefore this command must be issued at the power-up sequence.The state of pins BS0,1 and
A11~A0 in the same cycle is the data written to the mode register.One clock cycle is required to complete the write
in the mode register (refer to the following figure).The contents of the mode register can be changed using the
same command and the clock cycle requirements during operation as long as all banks are in the idle state.
Integrated Circuit Solution Inc.
15
DR038-0C 02/01/2005