Altera Avalon Tri-State Conduit Components - Manual (Page 5)

May 2011 Altera Corporation Avalon Tri-State Conduit Components User Guide
Preliminary
1. Avalon Tri-State Conduit Components
The Avalon ® Tri-State Conduit components available in the Qsys component library
allow you to create on-chip controllers that connect to off-chip devices: The Generic
Tri-State Conduit Controller includes parameters that you can specify to control the
connected off-chip device, frequently a memory device. The Tri-State Conduit Pin
Sharer arbitrates between multiple connected tri-state controllers. It drives signals
from the selected controller to the Tri-State Conduit Bridge. The Tri-State Conduit
Bridge converts an on-chip encoding of tri-state signals into true bidirectional signals
on the PCB.
Figure 1–1 illustrates the use of these three Qsys components in an
Altera ® FPGA.
Figure 1–1. Qsys System Using the Generic Tri-State Controller, Tri-State Conduit Pin Sharer and Bridge
Note to Figure 1–1 :
(1) Refer to Figure 3–3 on page 3–2 for details of the logic that controls read_out and write_out .
Altera FPGA
TCM
Tristate Conduit
Pin Sharer
addr_out[20:0]
data_outen
data_out[31:0]
data_in[31:0]
read_out
write_out
request
grant
grant
request
addr_out[22:0]
data_outen
data_out[15:0]
data_in[15:0]
read_out
write_out
TCS
Tristate Conduit
Bridge
S
Generic Tristate
Controller
Customized
for 2 MByte
x32 SSRAM
CS
A[20:0]
D_EN
D[31:0]
DI[31:0]
Rd
Wr
Request
Grant
TCM
S
Grant
Req
A[22:0]
D_EN
D[15:0]
DI[15:0]
Rd
Wr
TCM
chipselect_out
chipselect_out
irq_in
Generic Tristate
Controller
Customized
for 8 MByte
x16 Flash
addr_out
data_out
data_in
data_outen
chipselect_out
request
grant
irq_in
chipselect_out
write_out
read_out
clock
Note (1)
Avalon-MM
Master
TCS
TCS
CS
IRQ
Arb
Avalon-MM Slave S
TCM Tristate Conduit Master
Tristate Conduit Slave TCS