8–4
Chapter 8: Reset and Clocks
Reset
Stratix V Hard IP for PCI Express
June 2012
Altera Corporation
illustrates the RX transceiver reset sequence.
As
illustrates, the RX transceiver reset includes the following steps:
1. After
busy_xcvr_reconfig
is deasserted and
rx_pll_locked
is asserted, the
LTSSM state machine transitions from the Detect.Quiet to the Detect.Active state.
2. When the
pipe_phystatus
pulse is asserted and
pipe_rxstatus[2:0]
= 3, the
receiver detect operation has completed.
3. The LTSSM state machine transitions from the Detect.Active state to the
Polling.Active state.
4. The Hard IP for PCI Express asserts
rx_digitalreset
. The
rx_digitalreset
signal
is deasserted after
rx_signaldetect
is stable for a minimum of 3 ms.
illustrates the TX transceiver reset sequence.
Figure 8–3. RX Transceiver Reset Sequence
busy_xcvr_reconfig
rx_pll_locked
rx_analogreset
ltssmstate[4:0]
txdetectrx_loopback
pipe_phystatus
pipe_rxstatus[2:0]
rx_signaldetect
rx_freqlocked
rx_digitalreset
3
0
01
Figure 8–4. TX Transceiver Reset Sequence
npor
pll_locked
npor_serdes
127 cycles
tx_digitalreset