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2014
congatec
AG
TA30m16
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6.1.3
congatec Board Controller (cBC)
The conga-TCA3 is equipped with a Texas Instruments Tiva™ TM4E1231H6ZRBI microcontroller. This onboard microcontroller plays an
important role for most of the congatec BIOS features. It fully isolates some of the embedded features such as system monitoring or the I²C
bus from the x86 core architecture, which results in higher embedded feature performance and more reliability, even when the x86 processor
is in a low power mode. It also ensures that the congatec embedded feature set is fully compatible amongst all congatec modules.
6.1.3.1
Board Information
The cBC provides a rich data-set of manufacturing and board information such as serial number, EAN number, hardware and firmware revisions,
and so on. It also keeps track of dynamically changing data like runtime meter and boot counter.
6.1.3.2
General Purpose Input/Output
The conga-TCA3 offers general purpose inputs and outputs for custom system design. These GPIOs are multiplexed with SD signals and are
controlled by the cBC.
6.1.3.3
Fan Control
The conga-TCA3 has additional signals and functions to further improve system management. One of these signals is an output signal called
FAN_PWMOUT that allows system fan control using a PWM (Pulse Width Modulation) output. Additionally, there is an input signal called
FAN_TACHIN that provides the ability to monitor the system's fan RPMs (revolutions per minute). This signal must receive two pulses per
revolution in order to produce an accurate reading. For this reason, a two pulse per revolution fan or similar hardware solution is recommended.
Note
1. Use a 4-wire fan to generate the correct speed readout.
2. For the correct fan control implementation (FAN_PWMOUT, FAN_TACHIN), see the COM Express Design Guide.
6.1.3.4
Power Loss Control
The cBC has full control of the power-up of the module and therefore can be used to specify the behavior of the system after an AC power loss
condition. Supported modes are “Always On”, “Remain Off” and “Last State”.
