Altera Stratix GX Transceiver - Manual (Page 284)

9–58 Altera Corporation
Stratix GX Transceiver User Guide January 2005
Power Down
PMA loop
back
Serial loop
back
Tri-state (4)
toggle
Low (5) — —
Reverse
serial loop
back
Transmitter (6) Receiver — —
Notes to Table 9–2 :
(1) Either leave these pins floating or connect n_leg to GXB_GND through a 10-k Ω resistor and connect p_leg to
GXB_VCC through a 10-k Ω resistor to improve the device’s immunity to noise.
(2) Either leave these pins floating or connect refclkb(+) to GXB_GND through a 10-k Ω resistor and connect
refclkb(-) to GXB_VCC through a 10-k Ω resistor to improve the device’s immunity to noise.
(3) Altera recommends driving the reference resistor pin low for the powered down transceiver block.
(4) Transmitter output is tri-stated at the lowest V
OD
setting and is toggling at any other setting. However, the V
O D
is
80% of the selected V
O D
setting.
(5) Receiver pin is pulled low internally. It must be either left floating or pulled low externally.
(6) Only the 4-mA setting is supported for reverse serial loopback.
Table 9–2. I/O Pin States During Power-Down (Part 2 of 2)
Operation Transmitter Pins Receiver Pins REFCLKB Pins Rref Pin