Xilinx Virtex-5 RocketIO GTP User Manual page 118

Chapter 6: GTP Transmitter (TX)
Figure 6-16
absent conditions, along with the detection threshold.
When the PHY has completed the receiver detect sequence, it asserts PHYSTATUS for one
clock and drives the RXSTATUS signals to the appropriate code. After the receiver
detection is completed (as signaled by the assertion of PHYSTATUS), TXDETECTRX must
be deasserted.
RXPOWERDOWN[1:0]
TXPOWERDOWN[1:0]
118
illustrates the rise times associated with the receiver present and receiver
V
DD
rcvRef
V -V /2
DD SWING
Figure 6-16: Receive Detection Thresholds
Figure 6-17 shows this process.
TXUSRCLK2
TXDETECTRX
10b
PHYSTATUS
RXUSRCLK2
RXSTATUS[2:0] 000b
Figure 6-17: Receiver Detect Waveforms
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τ ≅ R
C < 180 ns
TERM CH
τ ≅ 2R
τ ≅ 1/2R
C
TERM CH
rcvDly
Virtex-5 RocketIO GTP Transceiver User Guide
Receiver Absent
Receiver Present
C > 6000 ns
TERM AC
Time
UG196_c6_16_071006
Status
UG196_c6_17_080806
UG196 (v1.3) May 25, 2007
R