Visible to Intel only — GUID: nik1398984279417
Ixiasoft
Visible to Intel only — GUID: nik1398984279417
Ixiasoft
17.10. Transceiver Reconfiguration Controller DFE Registers
This mechanism allows DFE to boost the signal to noise ratio of the received data. You can use DFE in conjunction with the receiver's linear equalization and with the transmitter's pre-emphasis feature. DFE is supported by Arria V GZ and Stratix V devices.
DFE automatically runs offset calibration and phase interpolator (PI) phase calibration on all channels after power up. You can run DFE manually to determine the optimal settings by monitoring the BER of the received data at each setting and specify the DFE settings that yield the widest eye.
The following table lists the direct DFE registers that you can access using Avalon-MM reads and writes on reconfiguration management interface.
Reconfig Addr | Bits | R/W | Register Name | Description |
---|---|---|---|---|
7’h18 | [9:0] | RW | logical channel address | The logical channel address. Must be specified when performing dynamic updates. The Transceiver Reconfiguration Controller maps the logical address to the physical address. |
7’h1A | [9] | R | control and status | Error.When asserted, indicates an invalid channel or address. |
[8] | R | Busy. When asserted, indicates that a reconfiguration operation is in progress. | ||
[1] | W | Read. Writing a 1 to this bit triggers a read operation. | ||
[0] | W | Write. Writing a 1 to this bit triggers a write operation. | ||
7’h1B | [5:0] | RW | dfe_offset | Specifies the 6-bit offset of the DFE register. |
7’h1C | [15:0] | RW | data | Reconfiguration data for the transceiver PHY registers. |
The following table describes the DFE registers that you can access to change DFE settings.
Offset | Bits | R/W | Register Name | Description |
---|---|---|---|---|
0x0 | [1] | RW | power on | Writing a 0 to this bit powers down DFE in the channel specified. |
[0] | RW | adaptation engine enable | Writing a 1 enables the adaptive equalization engine. | |
0x1 | [3:0] | RW | tap 1 | Specifies the coefficient for the first post tap. The valid range is 0–15. |
0x2 | [3] | RW | tap 2 polarity | Specifies the polarity of the second post tap as follows:
|
[2:0] | RW | tap 2 | Specifies the coefficient for the second post tap. The valid range is 0–7. | |
0x3 | [3] | RW | tap 3 polarity | Specifies the polarity of the third post tap as follows:
|
[2:0] | RW | tap 3 | Specifies the coefficient for the third post tap. The valid range is 0–7. | |
0x4 | [3] | RW | tap 4 polarity | Specifies the polarity of the fourth post tap as follows:
|
[2:0] | RW | tap 4 | Specifies the coefficient for the fourth post tap. The valid range is 0–7. | |
0x5 | [2] | RW | tap 5 polarity | Specifies the polarity of the fifth post tap as follows:
|
[1:0] | 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. |