IBM licenses Rambus XDR interface
Preparing PlayStation 3 parts?
IBM has licensed a key component of Rambus' XDR memory technology, the XIO memory controller interface cell.
It's perhaps no great surprise. Sony is an XDR licensee and is to use the high-speed consumer electronics-oriented memory technology in next year's PlayStation 3 console. The 256MB of XDR DRAM in the machine will be placed at the disposal of the unit's CPU, the IBM co-designed Cell processor.
Since IBM is making the system logic chippery, not to mention the PowerPC-derived processor, it needs some way of controlling the XDR, hence the need to licence XIO. The chipset will be fabbed at 90nm, reading between the lines of Rambus' press announcement.
XIO is separate from the memory controller, instead maintaining providing the link between the memory and the device that manages it. According to Rambus, the XIO "provides a wide, on-chip, CMOS-level signalling interface to the memory controller logic and a narrow, high-speed Differential Rambus Signalling Level interface to the external XDR memory system". ®