National Instruments NI PXI PCI-1411 SDRAM, Trigger Control and Mapping Circuitry, Acquisition, Scaling, ROI, Scatter-Gather DMA Controllers, Bus Master PCI Interface

Chapter 2 Hardware Overview

The color-space processor can export the video data in 32-bit RGB or HSL

formats or in individual 8-bit hue, saturation, or luminance planes. For

more information on these image types, see the Image Representations

section in AppendixA, Introduction to Color.

SDRAM

The NI 1411 comes with 16 MB of onboard high-speed synchronous

dynamic RAM (SDRAM). The NI 1411 can use the onboard RAM as a

first-in first-out (FIFO) buffer, transferring the image data as it is acquired

or acquiring the image data into SDRAM and holding it for later transfer to

main memory.

Trigger Control and Mapping Circuitry

The trigger control monitors and drives the external trigger line. You can

configure this line to start an acquisition on a rising or falling edge and

drive the line asserted or unasserted, similar to a digital I/O line. You can

also map many of the NI 1411 status signals to this trigger line and program

the trigger line in polarity and direction.

Acquisition, Scaling, ROI

The acquisition, scaling, and region-of-interest (ROI) circuitry monitors

the incoming video signals and routes the active pixels to the SDRAM

memory. The NI 1411 can perform ROI and scaling on all video lines and

frames. Pixel and line scaling transfers certain multiples (two, four, or

eight) of pixels and lines to onboard memory. In an ROI acquisition, you

select an area within the acquisition window to transfer to the PCI bus.

Scatter-Gather DMA Controllers

The NI 1411 uses three independent onboard direct memory access (DMA)

controllers. The DMA controllers transfer data between the onboard

SDRAM memory buffers and the PCI bus. Each of these controllers

supports scatter-gather DMA, which allows the DMA controller to

reconfigure on-the-fly. Thus, the NI 1411 can perform continuous image

transfers directly to either contiguous or fragmented memory buffers.

Bus Master PCI Interface

The NI 1411 implements the PCI interface with a National Instruments

custom application-specific integrated circuit (ASIC), the PCIM ITE. The

PCI interface can transfer data at a maximum rate of 132 Mbytes/s in

bus master mode. The NI 1411 can generate 8-, 16-, and 32-bit memory