National Instruments PCI-1428 - Manual (Page 23)

Chapter 3 Hardware Overview
IMAQ PCI-1428 User Manual 3-4 ni.com
Acquisition, Scaling, ROI
The acquisition, scaling, and region-of-interest (ROI) circuitry monitors
the incoming video signals and routes the active pixels to the multiple-tap
data formatter and SDRAM memory. The PCI-1428 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 across the PCI bus to system memory.
Scatter-Gather DMA Controllers
The PCI-1428 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. The PCI-1428 can perform continuous image
transfers directly to either contiguous or fragmented memory buffers.
Bus Master PCI Interface
The PCI-1428 implements the PCI interface with a National Instruments
custom application-specific integrated circuit (ASIC), the PCI MITE.
The PCI interface can transfer data at a maximum rate of 132 Mbytes/s
in bus master mode. The PCI-1428 can generate 8-, 16-, and 32-bit
memory read and write cycles, both single and multiple. In slave mode,
the PCI-1428 is a medium-speed decoder that accepts both memory and
configuration cycles. The interface logic ensures that the PCI-1428 meets
PCI loading, driving, and timing requirements.
Board Configuration NVRAM
The PCI-1428 contains onboard nonvolatile RAM (NVRAM) that
configures all registers on power-up.
Video Acquisition
The PCI-1428 can acquire digital video in a variety of modes and store the
images in the onboard SDRAM memory or transfer the images directly to
PCI system memory.