Settop cable television control device and method including bootloader software and code version table for maintaining and updating settop receiver operating system software

#The present invention relates generally to cable television, and, more particularly, to a settop receiver and method including a software component and frequency acquisition method for updating settop receiver operating system software.

#Cable television systems typically employ a receiver, or settop box, at each customer premises to receive and decode the programming transmitted to the user from a central location (commonly referred to in the industry as the “headend”) via the cable infrastructure. The settop box typically includes a receiver, decoder, processing circuitry and operating system software. The settop box is capable of receiving the programming information via the cable and transforming the received signal to a format that can be presented to the viewer via a television set. The operating software contained in conventional settop boxes is typically contained in a memory device and is fixed at the time the settop box is manufactured. This arrangement is sometimes referred to as “firmware” because to change, or upgrade, the operating software requires the removal of the existing memory device and the insertion of a new device containing the new or upgraded software code.

#Similarly, problems with the software code that may render the settop box unable to receive and decode the programming signal can be remedied only by replacing the device containing the code, or by requiring a separate communication link between the headend and the settop box for remotely programmable memory elements. If the code resides in firmware, then manual removal and replacement is required. Unfortunately, replacing the software code requires a costly trip to the customer location to perform the change, or requires that the customer return the settop box to a facility to have the repair performed. Similarly, upgrading the operating software code via a separate communication link is costly and inefficient. Using this method, updating settop box groups, or settop boxes from different manufacturers becomes impossible.

#The preferred embodiment of the invention, as defined in the claims, can be better understood with reference to the following drawings. The components within the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the present invention.

#FIG. 1 is block diagram illustrating the cable television system architecture in which the bootloader of the preferred embodiment of the invention resides;

#FIG. 2 is a block diagram illustrating the layout of the contents of the flash memory (in which the bootloader of the preferred embodiment of the invention is located) and DRAM of FIG. 1, while the DRAM is used during a download operation;

#FIG. 1 is block diagram illustrating the architecture of the cable television system 100 in which the software code, hereinafter referred to as “bootloader” code, or “bootloader”, of the preferred embodiment of the invention resides. Cable television system 100 includes central distribution point, or head end, 101 connected via connection 102 to settop receiver 150. Head end 101 is responsible for video distribution and provides control functions to settop receiver 150, the control functions including the assigning of rights to the settop receiver 150 and downloading software to the settop receiver 150. Connection 102, while illustrated as a single connection, includes a single direction downstream quadrature amplitude modulation (QAM) channel over which program video data is transmitted from the headend 101 to the settop receiver 150. Connection 102 also includes a bi-directional quadrature phase shift keying (QPSK) communication channel over which control information is exchanged between the headend 101 and the settop receiver 150. In addition, many intermediate devices and types of network transport mediums are also typically included in the connection 102, as would be understood by those reasonable skilled in the art of the present invention. As illustrated by out-of-band (OOB) transceiver 105, the exchange of information using the QPSK channel of connection 102 is independent of the QAM channel to which the settop receiver 150 is tuned.

#Settop receiver 150 includes tuner 104, which receives the radio frequency (RF) signal via connection 102 and delivers the RF signal via connection 109 to QAM receiver 106. QAM receiver 106 decodes the QAM signal received over connection 109 and provides, over connection 111, a digital data stream to filter block and (direct memory access) DMA channels 108. Filter block and DMA channels 108 are part of the broadband interactive processor (BIP) 107. The BIP 107 also includes central processing unit (CPU) 119.

#The CPU 119 communicates with dynamic random access memory (DRAM) 250, non-volatile random access memory (NVRAM) 126 and with flash memory 200 via communication bus 114. The BIP 107 also communicates via serial control bus 116 to control the operation of tuner 104 and QAM receiver 106. The BIP 107 also communicates, via connection 117, the received digital data stream from QAM receiver 106 to MPEG decoder 112 for transmission to a television set. Except as noted herein, the operation of tuner 104, QAM receiver 106, BIP 107 and CPU 119 are conventional and are known to those skilled in the art of cable television systems.