Video Memory; Video Selector And Mapper (Z10 Only); Digital-To-Analog Converter - Intergraph RealiZm Graphics Z10 Hardware User's Manual

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system performance. The pixel data consists of color (Red, Green, Blue, and Alpha - RGBA)
and depth (Z) data.
The resolver examines pixel data from the input FIFO and determines if it should write the
pixel data to the video memory. The resolver performs Z, mask, stencil (Z13, Z25, and V25
only), and alpha tests to determine if data should be written.
The resolver can perform an Arithmetic and Logic Unit (ALU) operation between the source
data (data from the Graphics Engine) and the destination data (data in video memory). The
operations include logical operations and OpenGL style alpha blend operations.
The resolver performs several different types of memory accesses including reads, writes, or
read-modify-writes. It conserves memory bandwidth by choosing an appropriate type.

Video Memory

The core of the frame buffer is video memory. Resolvers control the flow of data to and from
the video memory. The various implementations of RealiZm accelerators have varying
amounts of video memory: 48 VRAMs provide 12 MB of video memory for Z10; 8 SDRAMs
provide 16 MB of video memory for Z13; and 16 SDRAMs provide 32 MB of video memory
for Z25 and V25.
Video memory stores each pixel with a maximum of 128 bits (Z13, Z25, and V25).

Video Selector and Mapper (Z10 Only)

The display subsystem consists of the VSM ASIC and the DAC. The VSM ASIC receives
pixel data from the video memory. It selects the buffer (front or back), and the data (image or
overlay) to display. The video selection planes select one of the VSM's four video lookup
tables (VLTs) to map the image data. The VSM sends the mapped result to the DAC.

Digital-to-Analog Converter

The DAC converts pixel data into an analog voltage and sends it to the monitor for display.
The DAC also provides a user-definable 64 x 64 pixel hardware cursor.