
10–14 Chapter 10: Low Latency PHY IP Core
Dynamic Reconfiguration
Altera Transceiver PHY IP Core November 2012 Altera Corporation
User Guide
Dynamic Reconfiguration
As silicon progresses towards smaller process nodes, circuit performance is affected
more by variations due to process, voltage, and temperature (PVT). These process
variations result in analog voltages that can be offset from required ranges. The
calibration performed by the dynamic reconfiguration interface compensates for
variations due to PVT.
Each channel and each TX PLL have separate dynamic reconfiguration interfaces. The
MegaWizard Plug-In Manager provides informational messages on the connectivity
of these interfaces. Example 10–1 shows the messages for a single duplex channel.
Although you must initially create a separate reconfiguration interface for each
channel and TX PLL in your design, when the Quartus II software compiles your
design, it reduces the number of reconfiguration interfaces by merging
reconfiguration interfaces. The synthesized design typically includes a
reconfiguration interface for at least three channels because three channels share an
PMA Control and Status Registers
0x061 [31:0] RW
phy
_
serial
_
loopback
Writing a 1 to channel <
n
> puts channel <
n
> in serial
loopback mode. For information about pre- or
post-CDR serial loopback modes, refer to Loopback
Modes.
0x063 [31:0] R
pma_rx_signaldetect
When channel <n> =1, indicates that receive circuit for
channel <n> senses the specified voltage exists at the
RX input buffer.
0x064 [31:0] RW
pma_rx_set_locktodata
When set, programs the RX CDR PLL to lock to the
incoming data. Bit <n> corresponds to channel <n>.
0x065 [31:0] RW
pma_rx_set_locktoref
When set, programs the RX CDR PLL to lock to the
reference clock. Bit <n> corresponds to channel <n>.
0x066 [31:0] RO
pma_rx_is_lockedtodata
When asserted, indicates that the RX CDR PLL is
locked to the RX data, and that the RX CDR has
changed from LTR to LTD mode. Bit <n> corresponds
to channel <n>.
0x067 [31:0] RO
pma_rx_is_lockedtoref
When asserted, indicates that the RX CDR PLL is
locked to the reference clock. Bit <n> corresponds to
channel <n>.
Table 10–13. Low Latency PHY IP Core Registers (Part 2 of 2)
Word
Addr
Bits R/W Register Name Description
Example 10–1. Informational Messages for the Transceiver Reconfiguration Interface
PHY IP will require 2 reconfiguration interfaces for connection to the external
reconfiguration controller.
Reconfiguration interface offset 0 is connected to the transceiver channel.
Reconfiguration interface offset 1 is connected to the transmit PLL.
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