OptoRing
PC interface card.
As part
of the CCD3 camera system, the PCIFS2 card is the hardware tool making
it
possible for the host computer to communicate with the camera
controller as well
as grabbing the data transmitted in realtime from the controller. The
data-transport media is, as in the controller, the OptoRing. To ensure
that no
data is lost, no matter what the host computer is doing, a local memory
is used
as data buffer.
All the
necessary logic is placed in a FPGA ( Altera EP3C16 ), see figure.
Using
Altera’s SOPC concept, following building blocks are connected to an
Avalon
switch fabric:
·
PCI
to Avalon bridge. Altera ip
·
DDR-SDRAM
controller
Altera ip
·
OptoRing2
custom
module
Basic Board/FPGA
features
To
configure the EP3C16, an EPCS16 (16Mbit serial memory), an active
serial
interface, and a JTAG interface is available. This setup allows for the
addition
of a NIOS2 processor if that later becomes desirable. Local timing is
derived
from a 40MHz oscillator. All logic is interconnected by an Avalon
switch fabric
allowing several bus-masters to be active simultaneously. The Avalon is
running
120MHz.
Interfaces
to the PCI-bus and to the external fiberoptics is powered by the PCI
3.3V rail,
which also is the source for the local 1.2V FPGA core power-supply, the
2.5V
supply for the DDR-SDRAM and its interface and the DDR 1.25V active bus
termination. The fiberoptical parts itself are powered by the PCI
5V-rail. Thus
the board it both a 3.3V and 5V device.
Frame buffer
memory.
The board contains room for 4 DDR-DRAM chips distributed
in two banks. One ( Bank 0) or two banks can be populated. The chips
can be
either 64M x 8bit or 256M x 8bit ( TSOP66 package), allowing for a
capacity
ranging from 128 to 1024 Mbytes. This memory is intended to act as a
frame
store, ensuring that data is properly received independent of any other
activity in the PC.
Control registers.
The PCI to Avalon bridge is powering up as a 'simple
communication controller' during PCI
BIOS configuration. It will sign in as:
·
Device ID = 0x4F52 ( ASCII for 'OR' )
·
Vendor ID
=
0x1172 ( ALTERA id )
·
Function
078000 ( Simple
communication controller )
Use PCI-bios calls to get
access to the configuration data. Two BAR’s are assigned to the board:
·
BAR0 is the base address of the frame buffer memory
·
BAR1
is the base address of the OptoRing2 module ( se OptoRing
for register layout).