Introduction
1.0 Introduction
The VIDC20 offers the video system designer a flexible, high performance video controller for power and cost sensitive applications. The VIDC20 can be incorporated within a broad family of end products each with varying degrees of video requirements (e.g Portable LCD system through to higher performance Super VGA desktop products.).
The VIDC20 flexible bus interface provides hardware support for interfacing to mixed memory systems (e.g. VI2AM and DRAM) in conjunction with an external memory controller. The device also incorporates two stereo sound systems - an 8-bit (logarithmic) system, featuring up to eight channels each with its own stereo position, and an serial sound output port suitable for connection to an external CD DAC.
VIDC20 has a 64 bit data bus allowing a high data bandwidth (160 MSyte/s) from an external memory system. VIDC20 takes data from these memory banks under DMA control. VIDC20 will however work with a 32 bit data bus, at a correspondingly lower bandwidth. Hence an entry level system is possible containing only one bank of DRAM. For higher resolution displays, VIDC20 can take its video data from VRAM, and on-chip hardware support is provided for this.
1.1 Typical System Configurations
I	1	1	~ 32	1 vtDC20
32 VIDC20	DRAM
DRAM
A Mamory Control
32
32
Memory	DRAM Control
DRAM 1	32	~ VIDC20 ---~i
Memory Control
VRAM
Figure 1: Typical Memory System Configurations