by Anna Filatova
04/16/2002 | 11:51 PM
While JEDEC Committee is considering the necessity of approving DDR400 (DDR I) standard, the memory makers continue producing their chips absolutely freely. Especially, since there is a new chipset in the market "officially" supporting DDR400 memory: SiS645DX.
As I read over at this French site, Kingmax, which has been shipping DDR400 chips and modules with the standard CAS=2.5 (KDL684T4A2A-05), is about to start supplying DDR400 with CAS=2 (KDL684T4AA-50). Moreover, they claim that if you set CAS equal to 2.5 the memory modules will work at the frequency up to 233MHz DDR (DDR466 aka PC3700).<%BANNER[article]%>
It will be possible to distinguish between CAS2.5 and CAS2 chips by the marking mentioned above (The chips will be MicroBGA, as usual). Well it’s high time JEDEC approved of DDR466 (DDR I) standard already, and they are still thinking about DDR400 blaming some potential reliability issues for the delay.
It is also the right time to start using BGA packaging for the chips, as it will allow reducing the EMI significantly due to better contact with the PCB. Though another problem crops up in this case: will it be possible to solder the chip off the PCB once it is considered defective, but this is another story already.