Wireless radio modem with minimal interdevice RF interference

• US 5,727,020 A
• Filed: 11/13/1996
• Issued: 03/10/1998
• Est. Priority Date: 11/14/1994
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Jarmuszewski, Perry, Lazaridis, Mihal, Zhu, Lizhong, Taylor, Bryan, Wandel, Matthias, Edmonson, Peter, Carkner, Steven
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US08/747,874
• Time in Patent Office: 482 Days
• Field of Search: 375/222, 375/316, 455/343, 395/750
• US Class Current: 375/222
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04L 7/046 using a dotting sequence
• CPC Class Codes: H04W 52/028 switching on or off only a part of the equipment circuit blocks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless radio modem for incorporation into a host system includes radio frequency modulation/demodulation circuitry employing electronic device elements that operate in a frequency range that minimize the RF interference between the radio modem and the host system. Radio modem power conservation is further maximized by 1) simplifying signal modulation processing by use of a single sideband suppressed carrier waveform transition table, thereby reducing processing requirements; and 2) incorporating a "sleep mode" feature in which all non-timer circuitry is powered-down when not in use.

Claims

1. A circuit for minimizing power consumption in a radio modem that includes a digital signal processor and a microprocessor for providing overall control of the radio modem, wherein the microprocessor includes a nonmaskable interrupt signal input and at least one standard interrupt signal input and wherein power consumption is minimized by placing the microprocessor in an fully inactive mode when it is not needed to process a data transmission from a host system associated with the radio modem or to process an external signal received by the radio modem, the circuit comprising:

(a) deactivating means for placing the microprocessor in the fully inactive mode;

(b) a serial communications controller, connected to the microprocessor, for detecting communications from a host system associated with the radio modem and for generating a first activating interrupt signal if the communications are received while the microprocessor is in the fully inactive mode and for generating a first nonactivating interrupt signal if the microprocessor is in an active mode;

(c) timing means associated with the serial communications controller for producing an output pulse to the microprocessor after a predetermined period of time has elapsed from a point in time that the means for deactivating placed the microprocessor in the fully inactive state, wherein the output pulse is transmitted as a second activating signal if the microprocessor is fully inactive and as a second nonactivating signal if the microprocessor is active; and

(d) means for masking from the nonmaskable interrupt input to the microprocessor a received one of the first nonactivating interrupt signal or the second nonactivating interrupt signal.