COMe-bTL6 - User Guide. Rev. 1.5
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Features and Interfaces
3.1.
ACPI Power States
ACPI enables the system to power down and save power when not required (suspend) and wake up when required
(resume). The ACPI controls the power states S0-S5, where S0 has the highest priority and S5 the lowest priority.
The COMe-bTL6 supports ACPI 6.0 and the power states S0, S3, S4, S5 only.
Not all ACPI defined power states are available.
Systems that support the low-power idle state do not use power states S3 and S4.
Table 30: Supported Power States Function
S0
Working state
S3
ACPI suspend to RAM state
S4
Suspend-to-disk/Hibernate
S5
Soft-off state
To power on from states S3, S4 and S5 use:
Power Button
WakeOnLAN (S3, S4)
The OS must support wake up from a USB device and the carrier board must power the USB
port with the standby voltage.
3.2.
eSPI (option)
The eSPI interface from the PCH supports an external SIO and is pin shared with the LPC interface signal. To switch
from one interface to another, requires a hardware modification in the form of additional resistors. The modules
signal ESPI_EN# on pin-B47 indicates whether ESPI-mode or LPC-mode is enabled/disabled. The LPC interface is the
default connection from the embedded controller to the COMe connector.
In eSPI mode “ESPI_EN#” connects to ground on the carrier. The module uses pull-up resistors on this signal to detect
the mode.
If
ESPI_EN# selection on the carrier does not match the module configuration (eSPI/LPC) the
module is unable to boot.
3.3.
Fast I2C
The internal I2C bus transfers data between components on the same module and the external I2C bus transfers data
between I2C devices connected on the bus. The Fast I2C bus transfers data with rates up to 400 kHz.
To change the I2C bus speed, in the BIOS setup menu select:
Advanced>Miscellaneous>I2C Speed> 400 kHz to 1 kHz
The default speed is 200 kHz.