Method for power down interrupt in a data modem
An improved data modem (IDM) and method includes a communication processor module, a mass storage module, a power converter module, and one or more DSP modules. The communication processor module utilizes commercial off-the-shelf components as well as electrically programmable logic devices (EPLD), which are programmed to provide a watchdog timer, programmable interrupt controller, flash page addressing, ISA bus decoder and controller, and various circuits and logic.
1. A method for power down interrupt in a data modem, comprising:
detecting a power fault using detecting means in a power converter module;
generating a power-down interrupt signal and providing the power-down interrupt signal to a communication processor module;
receiving the power-down interrupt signal by a secondary interrupt controller in the communication processor module;
detecting a state in the power-down interrupt signal and generating an interrupt signal to a programmable interrupt controller;
providing an interrupt to a central processor vectored, via an interrupt descriptor table, to an interrupt request handler; and
effecting a response from an application-level power-down interrupt handler routine;
wherein the handler routine performs the steps of:
writing volatile information to a non-volatile storage; and
signaling an operating system to backup buffered data in a volatile memory to a non-volatile memory.
2. The method of claim 1 , further comprising:
scanning interrupt status and mask registers for pending, embedded interrupts; and
calling a corresponding interrupt handling routine.