User's Manual l TQMxE39S UM 0101 l © 2019 TQ-Group
Page 13
3.5.15
Serial Ports
The TQMxE39S offers up to four UARTs (Universal Asynchronous Receiver and Transmitter). The register set of SER0 and SER1 is
based on the industry standard 16550 UART. The UART operates with standard serial port drivers without requiring a custom
driver to be installed. The 16 byte transmit and receive FIFOs reduce CPU overhead and minimize the risk of buffer overflow and
data loss.
SER2 and SER3 are connected to the HSUART (High Speed UART) of the Intel
®
Atom
™
E3900, Intel
®
Pentium
®
N4200, or
Intel
®
Celeron
®
N3350 CPU.
TQ recommends preferring the usage of SER0 and SER1. There might be some problems with serial console when using the
Intel
®
HSUARTs.
3.5.16
Watchdog Timer
The TQMxE39S supports a freely programmable two-stage Watchdog timer, integrated in the TQ-flexiCFG block.
There are four operation modes available for the Watchdog timer:
•
Dual-stage mode
•
Interrupt mode
•
Reset mode
•
Timer mode
The timeout of the Watchdog timer ranges from 125 msec to 1 h.
The SMARC Specification does not support external hardware triggering of the Watchdog.
An external Watchdog Trigger can be configured to GPIO pins at the SMARC connector with the TQ-flexiCFG feature.
3.6
Connectors
3.6.1
SMARC Connector
A 314 pin 0.5 mm pitch card edge connector is realized on the TQMxE39S PCB. On the carrier board a connector mechanical
compatible to MXM3 graphic cards is used to contact the module. The stacking height is defined by the connector used on the
carrier (e.g. 1.5 mm, 2.7 mm, 5 mm, and 8 mm are available).
3.6.2
TQM Debug Card
The TQM debug card is designed to provide access to several processor and chipset control signals. The uEFI BIOS Power-On Self-
Test (POST) codes can be displayed through four hexadecimal display panels on the TQM debug card.
When the module is turned on, the hexadecimal display should show the uEFI BIOS POST codes. If the module does not boot, the
uEFI BIOS POST has detected a fatal fault and stopped. The number showing in the hexadecimal display on the TQM debug card
is the number of the test in which uEFI BIOS boot failed.
The debug card can be connected with an adaptor PCB in combination with the MB-SMARC-1.
Illustration 2:
TQM Debug Card
