Altera UG-01080 Guia do Utilizador Página 93

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Chapter 5: 1G/10 Gbps Ethernet PHY IP Core 5–5
Analog Parameters
November 2012 Altera CorporationAltera Transceiver PHY IP Core
User Guide
Speed Detection
Table 56 describes the parameters to specify speed detection parameters. By selecting
the Enable automatic speed detection option in the Megawizard, the PHY IP
implement Parallel Detect as described in the Ethernet specification. Selecting this
option causes the PHY to start in 10G mode and wait for a
link_good
signal from the
PCS. If the 10G link is not established within the time specified in the “Link fail inhibit
time for 10Gb Ethernet” setting, the sequencer (rate change) block makes a request to
reconfigure the channel to 1G mode. After reconfiguration, the PHY again checks for a
link_good
signal from the PCS for the amount of time specified by the “Link fail
inhibit time for 1Gb Ethernet” setting. This process continues until a link is achieved.
By default, at power-up, the channels are initialized to 10G mode.
The sequencer block is always monitoring the link status signals from each PCS and
requests reconfiguration any time link is lost. The 1G/10GbE PHY includes one
sequencer per channel.
Analog Parameters
Refer to the Chapter 18, Analog Parameters Set Using QSF Assignments for a
description of analog parameters that you can set using the Quartus II Assignment
Editor, the Pin Planner, or through the Quartus II Settings File (.qsf).
Table 5–6. Speed Detection
Parameter Name Options Description
Enable automatic speed
detection
On/Off
When you turn this option On, the core includes the sequencer block.
The sequencer (or rate change) block implements the Parallel Detect
function as defined by the Ethernet specification. This block monitors
the link status from each PCS. If link is lost, it reconfigures the channel
to 10G and 1G modes until the link is re-established.
Avalon-MM clock frequency
100–125 MHz
Specifies the clock frequency for
phy_mgmt_clk
.
Link fail inhibit time for 10Gb
Ethernet
504 ms
Specifies the time before
link_status
is set to
FAIL
or
OK
. A link fails
if the
link_fail_inhibit_time
has expired before
link_status
is
set to
OK
. For 10GBASE-KR the legal range is 500–510 ms. For more
information, refer to “Clause 73 Auto-Negotiation for Backplane
Ethernet” in IEEE Std 802.3ap-2007.
Link fail inhibit time for 1Gb
Ethernet
40–50 ms
Specifies the time before
link_status
is set to
FAIL
or
OK
. A link fails
if the
link_fail_inhibit_time
has expired before
link_status
is
set to
OK
. For 10GBASE-KR the legal range is 40–50 ms. For more
information, refer to “Clause 73 Auto-Negotiation for Backplane
Ethernet” in IEEE Std 802.3ap-2007.
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