Cirrus Logic is a fabless semiconductor supplier specializing in analog, mixed-signal, and DSP chips. They are presently headquartered in Austin, Texas. Their audio-processors are found in many home-theater receiver and other set-top box hardware. At one time, Cirrus Logic also designed and sold modem controllers, CD-drive controller chips, PC sound-card controllers, PC graphics chips. (Cirrus Logic has ended these business operations.)

Graphics Chipsets

In the early 1990s, Cirrus Logic was a leading supplier of low-cost PC graphics chips. Cirrus's Windows accelerators were among the fastest in the low-end market-segment, outperforming competing VGA-chips from Oak Technologies , Trident Microsystems, and Paradise (Western Digital.) For example, the Cirrus GD-5422 (1992) supported hardware acceleration for both 256-color and high-color (65,536 color) display-modes, one of the lowest-priced SVGA controllers to support both.

By the mid-1990s, when PC's had migrated to the PCI bus, Cirrus had fallen behind S3 and Trident Microsystems. When the announced release date of the GD-5470 "Mondello" came and went, Cirrus's reputation in desktop PC-graphics suffered. (Mondello would have been the company's first 3D-accelerator, but instead became vaporware.)

Later, the company provided the VGA-controller of the Voodoo Rush 3D-accelerator card. The Voodoo Rush card combined two separate graphics controller chips for legacy-VGA (2D) and 3D functionality. Both chips shared the same framebuffer memory. However, the Voodoo Rush was a marketing and technical disappointment. The company's final graphics chips, the GD-546x "Laguna" series of PCI/AGP 3D-accelerators, were novel in that they framebuffers used Rambus RDRAM instead of conventional SDRAM.

(This list is incomplete.)

DESKTOP

• 540? - SVGA chipset (ISA)
• 5420, 5422 - low-end Windows accelerator (ISA)
• 5424, 5426, 5428, 5429 - Windows accelerators (ISA, MCA, VL-Bus)
• 5430, 5432, 5434, 5436, 5440, 5446 - Windows accelerators (ISA, VL-Bus, PCI)
• 5464, 5465 - Windows 3D-accelerators (PCI, AGP)

MOBILE/LAPTOP

External Links

• http://www.cirrus.com/en/about/