iPEM
4.2 Gb SDRAM-DDR2
Austin Semiconductor, Inc.
AS4DDR264M64PBG1
RESET FUNCTION
(CKE LOW Anytime)
If CKE asynchronously drops LOW during any valid operation
(including a READ or WRITE burst), the memory controller
must satisfy the timing parameter tDELAY before turning off
the clocks. Stable clocks must exist at the CK, CK# inputs of
the DRAM before CKE is raised HIGH, at which time the
normal initialization sequence must occur. The DDR2
SDRAM device is now ready for normal operation after the
initialization sequence.
DDR2 SDRAM applications may go into a reset state
anytime during normal operation. If an application enters
a reset condition, CKE is used to ensure the DDR2 SDRAM
device resumes normal operation after reinitializing. All
data will be lost during a reset condition; however, the
DDR2 SDRAM device will continue to operate properly if
the following conditions outlined in this section are
satisfied.
The reset condition defined here assumes all supply
voltages (VDD, VDDQ and VREF) are stable and meet all DC
specifications prior to, during, and after the RESET
operation. All other input pins of the DDR2 SDRAM device
are a “Don’t Care” during RESET with the exception of
CKE.
Austin Semiconductor, Inc.
● Austin, Texas ● 512.339.1188 ● www.austinsemiconductor.com
AS4DDR264M64PBG1
Rev. 0.5 06/08
20
AUSTIN [ AUSTIN SEMICONDUCTOR ]
