MIPI D-PHY IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs

ID 817561
Date 3/30/2025
Public

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Document Table of Contents

7.4. Calibration

The MIPI D-PHY IP provides the following types of calibration:
  • Initial skew calibration
    • Required for bit rate > 1.5 Gbps; optional for bit rates below 1.5 Gbps.
    • Data pattern used is 1010… clock pattern.
    • Minimum duration of 2015 UI (maximum at 100 us)
  • Alternate calibration
    • Required for bit rate > 2.5 Gbps; optional for bit rates below 2.5 Gbps .
    • Data pattern used in PRBS9.
    • Minimum duration of 2015 UI (maximum at 100 us).
  • Periodic skew calibration
    • Optional at any bit rate.
    • Data pattern used is 1010…
    • Minimum duration of 210 UIs (maximum of 10 us).
  • Preamble
    • Required for bit rate > 2.5 Gbps; optional for bit rates below 2.5 Gbps.
    • Preamble data pattern of 1010… precedes every HS data packet.
    • Minimum duration of 32 UI (max of 512 UI).
Table 18.  D-PHY IP Calibration Support Matrix
Calibration Type Support Comment
Initial skew calibration Supported

MIPI D-PHY IP configurable

Rx: Adjust clock delay to center data window

Tx: Auto calibration logic starts when all lanes go to INIT done state calibration (protocol side can also initiate this using PPI. TxSkewCalHS)

Alternate calibration Supported

MIPI D-PHY IP configurable

Rx: Adjust clock delay to center data window; determine data dependent window edge shifts

Tx: Auto calibration logic starts after initial skew calibration (protocol side can also initiate this using PPI.TxAlternateCalHS)
Periodic skew calibration Supported

MIPI D-PHY IP configurable

Rx: Minor adjustment on window edges

Tx: Protocol controlled (using PPI.TxSkewCalHS)
Preamble Supported

MIPI D-PHY IP configurable

Rx: recognize preamble but will not make any adjustments

Tx: automatically inserts PREAMBLE for every HS transfer