VIDC : A Combined Video/Audio Processor Chip

This paper describes a custom VLSI video/audio controller device for low cost 32-bit personal computer applications. The video circuitry includes 32-bit FIFOs, video and cursor palette RAMs, fully programmable timing generation for pixel rates, screen composition and cursor size and 3 × 4-bit DACs capable of 50MHz pixel rates. The IC also contains a sound system which includes an 8-bit exponential DAC, giving 12-bit resolution, an eight channel stereo image register, and timing generation. The chip contains 18k transistors and has been fabricated on a 2.4um double layer metal, 5V CMOS process. It has been successfully demonstrated at pixel rates above 40MHz.