Advantech FWA-2320 User Manual page 36

2.4.5.3 Legacy Functions and IO
1. RTC
The SoC contains an MC146818B-compatible Real-Time Clock (RTC) with 256 bytes
of battery-backed RAM (CMOS RAM) which is reserved for legacy use. The real-time
clock keeps track of the system time. The RTC operates on a 32.768 KHz crystal and
is buffered by a 3.3 V coin battery (B1).
The typical current draw in the system off state equals 6uA which yields a maximum
system off time of 17520 hours based on the capacity of the battery used. Please
note that environmental conditions, especially temperature, can lead to a change of
current draw and that effects like battery self discharge current and other leakage
need to be factored in.
Please refer to section 3.5.2 reg. replacing the coin battery.
2. Serial Ports
The SoC integrates two 16C550 compliant UARTs which are mapped to the default
resources:
Table 2.14: COM Ports
UART Port
0 COM1
1 COM2
Please note that the UARTs in the SoC do not support any UART handshake and sta-
tus/control signals but RXD, TXD, only.
FWA-2320 User Manual
Figure 2.11 RTC battery
Resources
IO Range 0x3f8 -0x3ff, IRQ4
IO Range 0x2f7 – 0x2ff, IRQ3
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Implementation
Console port
Interface to LCM