COMe-bV26 - Rev. 1.0, User Guide
// 39
3.4.
Hardware Monitor (HWM)
The Nuvoton NCT7802Y Hardware Monitor (HWM) controls the health of the system by monitoring critical aspects
such as the module’s processor temperature using thermal resistors, power supply voltages and fan speed for
cooling.
The SMART FAN ™ technology controls the duty cycle of the fan output (FAN_PWMOUT) with temperature setting
points. This enables flexible fan control for cooling solutions and noise sensitive solutions. For system protection,
users can set threshold values for alarm signals.
The HWM is accessible using the SM Bus address 5Ch, see Chapter 4.2: System Management (SM) Bus.
3.5.
LPC
The LPC COMe connectors signal are used for external LPC on the carrier board on the carrier board.
3.6.
NVMe SSD Flash memory (Option)
The NVMe SSD Flash memory option supports up to 1 TByte of on-board Flash memory.
3.7.
Real Time Clock
The RTC keeps track of the current time accurately. The RTC’s low power consumption enables the RTC to continue
operation and keep time using a lower secondary source of power while the primary source of power is switched off
or unavailable.
Typical RTC values are 3 V and less than 10 μA. When powered by <mains power supply, the RTC voltage is generated
by on-module regulators, to reduce RTC current draw. The RTC’s battery voltage range is 2.8 V to 3.47 V.
The RTC battery input may be left open on the carrier board if an application does not
require the RTC to keep time when the main power source is off or unavailable.
3.8.
Serial Peripheral Interface
The Serial Peripheral Interface (SPI) bus is a synchronous serial data link where devices communicate in master/slave
mode, where the master device initiates the data frame. Multiple slave devices are allowed with individual slave
select (chip select) lines.
The SPI interface may only be used with a SPI Flash device to boot from the external BIOS on
the carrier board.
3.8.1.
SPI Boot
The SPI Flash device stores the BIOS to be booted. The COMe-bV26 supports a 16 MByte (128 Mbit) on-module and
carrier board SPI Flash devices. Optionally, a second on-module SPI can be implemented for additional safety.
The pins A34 (BIOS_DIS0#) and pin B88 (BIOS_DIS1#) configure the SPI Flash device to be used, see Table 15.