David Greenhill

A 64-b microprocessor with multimedia support

A 167 MHz 64 b VLSI CPU chip is described. The chip executes a 333-MFLOPS (peak) with an estimated system performance of 270SPECint92/380SPECfp92 (@167 MHz, 2 MB E-cache). The 17.7/spl times/17.8 mm die is fabricated with a 0.5 micron CMOS technology with four metal layers and contains 5.2 M transistors. The superscalar processor is capable of sustaining an execution rate of four instructions per cycle even in the presence of conditional branches and cache misses. Four fully pipelined 8/spl times/16 b multipliers and four single-cycle latency 16 b adders combine to speed up image processing, 2-D, 3-D graphics, video compression/decompression by up to an order of magnitude. High clock speed was obtained by the use of delayed reset logic, a new register file design; and novel comparators. Strict design methodology allowed fully functional first silicon which met all speed targets. The power dissipation of the chip is 28 W.

An 8-Core 64-Thread 64b Power-Efficient SPARC SoC

The 8-core 64-thread 64b power-efficient 2nd-generation Niagara SPARC SoC has 4MB L2 cache with one times8 PCI-Express, two 10G Ethernet (XAUI), and 8 FBDIMM ports. The on-chip SerDes provide greater than 1Tb/s bandwidth. The 500M transistor chip with a die size of 342mm 2 is implemented in a 11M 65nm triple-Vt CMOS process

A 40nm 16-core 128-thread CMT SPARC SoC processor

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.