13.1 Automatic I/O calibration is not functional

Automatic I/O calibration does not work properly and returns incorrect calibration values. As a consequence, the output impedance value is not reliable.

Work Around

Automatic I/O calibration has to be bypassed and calibration values must be forced manually.

Configure the controller as follows:
  1. Disable QSPI (QSPI_CR.QSPIDIS = 0x1).
  2. Disable register write protection (QSPI_WPMR = 0x51535000).
  3. Disable automatic I/O calibration during the refresh sequence (QSPI_PCALCFG.DAPCAL = 0x1).
  4. Define the calibration P-channel and N-channel bypass values and enable bypass:

    • QSPI_PCALBP.CALPBP = 0x9 when VDDQSPI0 is 1.8V, or

      QSPI_PCALBP.CALPBP = 0xD when VDDQSPI0 is 3.3V

    • QSPI_PCALBP.CALNBP = 0x4 when VDDQSPI0 is 1.8V, or

      QSPI_PCALBP.CALNBP = 0x2 when VDDQSPI0 is 3.3V

    • QSPI_PCALBP.BPEN = 0x1
  5. Enable register write protection (QSPI_WPMR = 0x51535007).
  6. Enable QSPI (QSPI_CR.QSPIEN = 0x1).

Affected Device Revisions

A0

A0-D1G

A0-D2G

A1

A1-D1G

A1-D2G

A1-D5M

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