User's Manual l TQMa8MxML UM 0103 l © 2022, TQ-Systems GmbH
Page 48
3.2.10
Impedances
By default, all single-ended signals have a nominal impedance of 50 Ω ±10 %.
However, some interfaces on the TQMa8MxML are routed with different impedances, depending on the signal requirements.
The following table is taken from the Hardware Developer's Guide (6) and shows the respective interfaces:
Table 41:
Impedances
Signal / Interface
Impedance on TQMa8MxML
Recommendation for carrier board
DDR DQS/CLK; PCIe TX/RX data pairs
85 Ω, differential
85 Ω ±10 %, differential
Differential USB signals
90 Ω, differential
90 Ω ±10 %, differential
Differential MIPI signals (CSI and DSI)
100 Ω, differential
100 Ω ±10 %, differential
Differential RGMII signals
100 Ω, differential
100 Ω ±10 %, differential
4.
SOFTWARE
The TQMa8MxML is delivered with a preinstalled boot loader U-Boot.
The
TQ-Systems GmbH is configured for the combination of TQMa8MxML and MBa8Mx.
The boot loader U-Boot provides TQMa8MxML-specific as well as board-specific settings, e.g.:
•
i.MX 8M Mini configuration
•
PMIC configuration
•
SDRAM configuration
•
eMMC configuration
•
Multiplexing
•
Clocks
•
Pin configuration
•
Driver strengths
Further information can be found in the
https://support.tq-group.com/TQMa8MxML
If another bootloader is used, this data must be adapted. Contact
for detailed information.
