Offset
Bits
R/W
Register Name
Description
0x4
[3]
RW
tap 4 polarity
Specifies the polarity of the fourth post tap as
follows:
• 0: negative polarity
• 1: positive polarity
[2:0] RW
tap 4
Specifies the coefficient for the fourth post tap.
The valid range is 0–7.
0x5
[3]
RW
tap 5 polarity
Specifies the polarity of the fifth post tap as
follows:
• 0: negative polarity
• 1: positive polarity
[2:0] RW
tap 5
Specifies the coefficient for the fifth post tap.
The valid range is 0–3.
0xB
[0]
RW
DFE_adaptation
Writing a 0 or 1 to this bit turns on the DFE
power and initiates triggered DFE mode for the
specified channel. Ensure busy bit is 0 to
complete the reconfiguration process. Reading
(0xB) register bit as 1 and busy bit as 0, indicates
that the DFE is in triggered mode. To turn off
the triggered DFE mode, write 0 to bit 1 of
register 0x0.
Controlling DFE Using Register-Based Reconfiguration
In register-based mode, you use a sequence of Avalon-MM reads and writes to configure the DFE and to
turn it on and off. There are three ways to control the DFE using a sequence of register-based
reconfiguration reads and writes.
Turning on DFE Continuous Adaptive mode
Complete the following steps to turn on DFE continuous adaptive mode:
1. Read the DFE control and status register busy bit (bit 8) until it is clear.
2. Write the logical channel number of the channel to be updated to the DFE logical channel number
register.
3. Write the
DFE_offset
address to 0x0.
4. Write the data value 2'b11 to the data register. This data powers on DFE and enables the DFE
continuous adaptation engine.
5. Write the
control and status
register write bit to 1'b1.
6. Read the
control and status
register
busy
bit. Continue to read the
busy
bit while its value is 1b’1.
7. When busy = 1’b0, the Transceiver Reconfiguration Controller has updated the logical channel
specified in Step 2 with the data specified in Steps 3 and 4.
16-22
Controlling DFE Using Register-Based Reconfiguration
UG-01080
2015.01.19
Altera Corporation
Transceiver Reconfiguration Controller IP Core Overview
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