||In modern graphics processing unit, the vertex shader is a quite important component. It is mainly responsible for the coordinate transformation and light’s geometric operations. When a graphics processing unit executes 3D graphics pipelining to generate a 3D image, the vertex shader usually has to perform a lot of floating-point arithmetic operations. Therefore, this thesis, proposes a scheme which is suitable for a multi-functional multi-precision 4D dot product unit with single instruction multiple data architecture compliant with IEEE754 standard for a single-precision floating-point arithmetic.|
The proposed 4D dot product unit can perform multiple instruction, including floating-point addition, floating-point multiplication, floating-point multiply-add, floating-point 3D dot product and floating-point 4D dot product. Multi-function means you can use one 4D dot product unit to perform one of five floating-point instruction. It is equivalent to fuse five independent arithmetic units into a hardware, to reduce area. In addition to multi-function, it also provides users four floating-point operation’s precision modes, which are 23-Bit, 18-Bit, 13-Bit, and 7-Bit. In low precision mode, graphics processing unit will generate distorted image, but human eyes can’t clearly identify a slight distortion of the rendered image. As a result, power and energy savings can be achieved by turning off a part of circuit and reducing the switching activities when a little image distortion is allowable.