Specifications

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Fig. 3.2: Depiction of the general firmware design.
3.3.1 Hardware I nterface Layer
The Hardware Interface Layer consists of mo dules that form the basic building blocks
of the entire firmware set. This layer should answer how a specific operation called by high
level tasks resolve into hardware action. All platform specific detail must be contained
herein to promote portability.
System Power Management
The purpose of the power management driver is to provide low-level support for in-
telligent power supply han dling and system clock handling. It must provide a means of
registering speed and power needs of the device and intelligently activating or deactivating
the appropriate resources. The module must shutdown the entire device when no needs are
registered.
RTC
The RTC functions as the heart beat of the entire system. It must not be stopped at
anytime durin g the p roduct’s lifetime. This code must utilize a timer resource with interrupt
capabilities, time register(s), and a periodic interrupt service handler that updates the time