cl-pd6833 Cirrus Logic, Inc., cl-pd6833 Datasheet - Page 29

• Manufacturer Part Number: cl-pd6833
• Description: Pci-to-cardbus Host Adapter
• Manufacturer: Cirrus Logic, Inc.

CL-PD6833
PCI-to-CardBus Host Adapter
3.1.3
The CL-PD6833 supports the implementation of the ZV (zoomed video) Port at the PC Card interface.
The ZV Port provides a direct connection between a PC Card, a VGA controller, and an audio DAC. It
allows the PC Card to directly write video data to a graphics controller input port and audio data to a dig-
ital-to-analog converter.
The CL-PD6833 supports the ZV Port in the ‘bypass’ mode, during which the signals are directly routed
from the PC Card bus to the video port of the VGA controller. Rerouting is accomplished by tristating
address lines A[25:4] from the CL-PD6833. The CL-PD6833 enters the ZV Port mode when the
Multimedia Enable bit (bit 0 of the Misc Control 1 register at index 16h or memory offset 816h) is set to
a ‘1’. The CL-PD6833 has a Multimedia Arm bit (bit 7 of the Misc Control 3 register at I/O index 2Fh,
Extended Index 25h, or memory offset 925h), which works as an overriding control bit. Until the
Multimedia Arm bit is set, the Multimedia Enable bit does not tristate the address pins as previously
described.
Figure 3-5
to the application note Zoomed Video Port Implementation (AN-PD10).
June 1998
Start Address Registers
End Address Registers
shows an example of the ZV Port implementation using the CL-PD6833. For more details, refer
System I/O Map
System I/O Map
Zoomed Video Port
ADVANCE DATA BOOK v0.3
Figure 3-4. R2 I/O-to-Memory Window Organization
*NOTE: The CL-PD6833 only decodes the first 64 Kbytes of the PCI I/O space.
PCI I/O Address Space
4 Gbytes*
I/O Window
.
.
.
.
64 Kbytes
Offset Address Registers
Card Memory Map
INTRODUCTION TO THE CL-PD6833
PC Card Memory Address Space
Card Memory Window
Common Memory
64 Mbytes
Attribute
Memory
29