Hierarchical pin sharing, Hierarchical pin sharing –4, Altera fpga – Altera Avalon Tri-State Conduit Components User Manual
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Chapter 3: Tri-State Conduit Pin Sharer
Hierarchical Pin Sharing
Avalon Tri-State Conduit Components User Guide
May 2011
Altera Corporation
Preliminary
Hierarchical Pin Sharing
provides the simplest use of the Tri-State Conduit Pin Sharer;
it multiplexes between two controllers. You can also create a design that includes
hierarchy of Tri-State Conduit Pin Sharers that access the same pins on the FPGA. In
Figure 3–5
, Sub-systems A and B each include two controllers that access off-chip
devices. The pin sharer in the Top Level system connects to a single Tri-State Conduit
Bridge that drives signals on the PCB.
Figure 3–5. Using The Tri-State Conduit Pin Sharer in Hierarchical Designs
Tri-state
Conduit
Pin Sharer
TCS
TCS
request
grant
Tri-state
Controller 1
TCM
request
grant
Tri-state
Controller 2
TCM
TCM
Tri-state
Controller 3
TCM
request
grant
request
grant
addr
write
read
data
request
grant
Tri-state
Controller 4
TCM
Tri-state
Conduit
Pin Sharer
TCS
TCS
TCM
Tri-state
Conduit
Pin Sharer
TCS
TCS
TCM
Tri-state
Conduit
Bridge
Device 1
Device 2
Device 3
Device 4
TCS
CN
request
request
grant
grant
Altera FPGA
Sub-system A
Sub-system B
Top Level
PCB