INTEGRATED SILICON SOLUTION (ISSI) IS43DR16640B-25DBLI SDRAM, DDR2, 1GBIT, 1.8V, 84BGA

The IS43DR16640B-25DBLI is a 1Gb DDR2 SDRAM with 400MHz frequency, DDR2-800D speed grade and 64Mb x 16 organization. For application flexibility, burst length, burst type, CAS# latency, DLL reset function, write recovery time (WR) are user defined variables and must be programmed with a Mode Register Set (MRS) command. Additionally, DLL disable function, driver impedance, additive CAS latency, ODT (On Die Termination), single-ended strobe and OCD (off chip driver impedance adjustment) are also user defined variables and must be programmed with an Extended Mode Register Set (EMRS) command. Contents of the Mode Register (MR) or Extended Mode Registers EMR[1] and EMR[2] can be altered by re-executing the MRS or EMRS Commands. Even if the user chooses to modify only a subset of the MR, EMR[1] or EMR[2] variables, all variables within the addressed register must be redefined when the MRS or EMRS commands are issued.