Chips Provide Clock Signals For Rambus Applications

A complete clock solution for Rambus memory-enabled applications has arrived in the form of a Direct Rambus clock generator (DRCG) chip and a CK98 system clock generator IC. The PCK2011 is a DRCG chip that provides differential clock signals of up to 400 MHz to Direct Rambus memory channels onto Rambus in-line memory modules (RIMMs). The PCK2010 is a spread-spectrum, CK98 system clock generator that provides 50/66-MHz single-ended clock signals to the DRCG, as well as several copies of the CPU, 3V66, PCI, IOAPIC and USB clocks.Through use of the I₂C bus, a clock generator user can select frequency, spread-spectrum mode, and individual DIMM enabling. The chips deliver low jitter, tight skews and spread-spectrum capabilities that reduce EMI on the board, it's claimed. Cycle-to-cycle jitter for the PCK2011 is