Matrox Electronic Systems II manual Data interfaces, Video Interface Asic, PCI interface

70 Chapter 5: Matrox Meteor-II hardware reference

	Data interfaces
	Video Interface ASIC
	With the exception of Meteor-II /1394, all Meteor-II boards have
	a VIA, which acts mainly as a bridge to the PCI bus. The VIA
	is capable of high-speed image transfers to Host memory or
	other PCI devices across the PCI bus. It uses 4 Mbytes of
	SGRAM (on-board memory) to store data until the PCI bus
	becomes available. On the PCI form factor, the VIA also
	supports image transfers across the VMChannel to one or more
	Matrox imaging boards for accelerated image processing or
	display.
	Matrox VIA can manage up to two simultaneous data streams.
Simultaneous data
streams	For example, it can grab into SGRAM, and concurrently
	transfer data over the VMChannel or PCI buses.
	The VIA is capable of plane separation of image input on two,
General features
	three, or four 8-bit or 16-bit components (for example, RGB
	packed to RGB planar). This mechanism is also used to merge
	line segments of monochrome multi-tap cameras.
	PCI interface
	Matrox Meteor-II has a 32-bit PCI bus interface, capable of a
	peak transfer rate of 132 Mbytes/sec.
	The VIA’s PCI interface is 32-bits wide and operates at 33 MHz.
The VIA’s PCI interface
	It allows all VIA resources to be accessed through a 128-Mbyte
	memory region, mappable anywhere in the 4-Gbyte PCI
	address space.
	In addition, the PCI interface support various plane and pixel
	transfer modes by using some of the VMChannel logic.
	Consequently, VMChannel and PCI transfers cannot be
	performed simultaneously.
	Read pre-fetch and write posting buffers are integrated to
	optimize Host access.