A 40nm 16-core 128-thread CMT SPARC SoC processor
Jinuk Luke Shin, Kenway W. Tam, Dawei Huang, Bruce Petrick, Ha Pham, Changku Hwang, Hongping Li, Alan P. Smith, Timothy Johnson, Francis Schumacher, David Greenhill, Ana Sonia Leon, Allan Strong · 2010
This next generation of Chip Multithreaded (CMT) SPARC SoC processor, code named Rainbow Falls, doubles on-chip thread count over its predecessor the UltraSparc T2+. The chip offers high levels of integration and scalability with twice the number of cores, a larger L2 cache, and higher maximum I/O bandwidth, within the same power envelope. Sixteen 8-threaded enhanced SPARC cores (SPC) provide 128 threads in a single die, delivering the highest thread count for a general-purpose microprocessor. The new cache coherency further allows up to 4-way glueless systems with a total of 512 threads. Each core communicates with the unified 6MB L2 cache through a crossbar (CCX) delivering 461GB/s (Fig. 5.2.1). A gasket (CXG) is also introduced to manage the congestion and synchronization of the massive interconnect between the 16 cores and the crossbar. This facilitates a synchronized delay control between any core and any L2 bank for partial core product binning and testing.