Verdin Development Board Errata
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Errata #9:
HAR-8342 – Stitching Capacitors Influence Verdin iMX8M Plus
Bluetooth Config Strapping
Affected Version:
Verdin Development Board V1.0B
Verdin Development Board V1.1A
Fixed in:
Verdin Development Board V1.1B
9.1
Customer impact
The Bluetooth solution of the Wi-Fi/Bluetooth-equipped Verdin iMX8M Plus SoM is not accessible
by the system as the host interface strapping signal of the Bluetooth solution is unintentionally
influenced by two stitching capacitors on the carrier board. This leaves the Bluetooth solution in the
UART interface mode instead of SDIO.
9.2
Description
The signal used for strapping the HCI (Host Controller Interface) configuration of the Bluetooth
solution at the time of powering up a Verdin iMX8M Plus SoM is also available on the Module-
specific pin MSP_8 (#104) of the SoM edge connector. Module-specific pins feature stitching
capacitors for providing current return paths for cases when those pins are being used for
accommodating high-speed signals.
The Verdin Development Board V1.1A features two such capacitors (C250, C313) on the MSP_8
signal. During powering up the system, the stitching capacitors delay the transition of the related
signal to the intended state and thus result in a wrong configuration being strapped. Instead of
SDIO mode, the host interface of the Bluetooth solution gets configured to UART mode. As a result,
the Bluetooth solution is not accessible by the system.
The strapping of the Wi-Fi/Bluetooth module of the Verdin iMX8M Mini SoM is not affected by the
stitching capacitors on MSP_8. The Verdin iMX8M Mini provides the strapping pin on the MSP_25,
which does not feature strapping capacitors.
9.3
Workaround
Remove the stitching capacitors C250 and C313 from the carrier board. This makes the Bluetooth
interface work in case the carrier board is connected to a Verdin iMX8M Plus SoM with a hardware
version of V1.0C or newer.
