SOYO SY-7VBA133U User Manual page 16

Motherboard Description SY-7VBA133U
AGP / PCI remapping control is also provided for operation under
protected mode operating environments. Both Windows-95 VXD and
Windows-98 / NT5 miniport drivers are supported for interoperability with
major AGP-based 3D and DVD-capable multimedia accelerators.
The VT82C694T supports two 32-bit 3.3 / 5V system buses (one AGP and
one PCI) that are synchronous / pseudo-synchronous to the CPU bus. The
chip also contains a built-in bus-to-bus bridge to allow simultaneous
concurrent operations on each bus. Five levels (doublewords) of post write
buffers are included to allow for concurrent CPU and PCI operation. For
PCI master operation, forty-eight levels (doublewords) of post write
buffers and sixteen levels (doublewords) of prefetch buffers are included
for concurrent PCI bus and DRAM/cache accesses. The chip also supports
enhanced PCI bus commands such as Memory-Read-Line,
Memory-Read-Multiple and Memory-Write-Invalid commands to
minimize snoop overhead. In addition, advanced features are supported
such as snoop ahead, snoop filtering, L1 write-back forward to PCI master,
and L1 write-back merged with PCI post write buffers to minimize PCI
master read latency and DRAM utilization. Delay transaction and read
caching mechanisms are also implemented for further improvement of
overall system performance.
The 352-pin Ball Grid Array VT82C686B PCI to ISA bridge supports four
levels (doublewords) of line buffers, type F DMA transfers and delay
transaction to allow efficient PCI bus utilization and (PCI-2.1 compliant).
The VT82C686B also includes an integrated keyboard controller with PS2
mouse support, integrated DS12885 style real time clock with extended
256 byte CMOS RAM, integrated master mode enhanced IDE controller
with full scatter / gather capability and extension to UltraDMA-33/66/100
for 33/66/100 MB/sec transfer rate, integrated USB interface with root hub
and four function ports with built-in physical layer transceivers,
Distributed DMA support, and OnNow / ACPI compliant advanced
configuration and power management interface.
The VT82C686B also includes an AC97 / MC97 link for interface to
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