2–220
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Reset Control and Power Down
Power Down
The Quartus II software automatically selects the power-down channel
feature, which takes affect when you configure the Stratix II GX device.
All unused transceiver and blocks in a design are powered down to
reduce the overall power consumption. You cannot use the power-down
feature on the fly to turn the transceiver channels and transceiver blocks
on and off without reconfiguration.
You can set the transceiver block to power down automatically in the
Quartus II software or to power down dynamically in the PLD fabric
through the
gxb_powerdown
port. Assertion of this port does not power
down the
refclk
reference clock buffer.
1
The
gxb_powerdown
port is optional. In simulation, if the
gxb_powerdown
port is not instantiated, you must assert
tx_digitalreset
,
rx_digitalreset
and
rx_analogreset
signals appropriately for correct simulation
behavior. If the
gxb_powerdown
port is instantiated and other
reset signals are not used, you must assert the
gxb_powerdown
signal for at least one parallel clock cycle for correct simulation
behavior. In simulation, you can de-assert the
rx_digitalreset
immediately after
rx_freqlocked
signal
goes high to reduce the simulation run time. It is not necessary
to wait for 4 us as suggested in the actual reset sequence.
1
In PIPE mode simulation, you must assert the
tx_forceelecidle
signal for at least one parallel clock cycle
before transmitting normal data for correct simulation behavior.
Table 2–53
lists the I/O pin states during power down for normal
operation, power down, and PMA lookback.
Table 2–53. I/O Pin States During Power-Down (Part 1 of 2)
Operation
Transmitter Pins
Receiver Pins
REFCLK Pins
Rref Pins
Normal operation
Transmitter
Receiver
Clk input
Ext. reference R
Power down
Tri-state
(1)
Tri-state
(1)
Tri-state
(2)
Low
(3)
Содержание Stratix II GX
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