Abstract: A compact, register-based, eight-bit virtual machine is realized on a resource-constrained device such as, for example, an IR remote control device. The IR remote control device includes a script interpreter, as well as loader API functionality and API functionality to support communication over a bidirectional link. The functionality of the remote control device is customized by loading either a machine code API routine and/or a script API routine onto the remote control device via the bidirectional link. A script is loaded via the bidirectional link and is stored in program memory. Once loaded, the script is interpreted by the virtual machine, thereby calling API functionalities provided, and thereby causing the remote control device to have a desired customized function. Providing the virtual machine on all the members of a family of remote control devices allows the same script to run on any remote control device of the family.

Abstract: A compact, register-based, eight-bit virtual machine is realized on a resource-constrained device such as, for example, an IR remote control device. The IR remote control device includes a script interpreter, as well as loader API functionality and API functionality to support communication over a bidirectional link. The functionality of the remote control device is customized by loading either a machine code API routine and/or a script API routine onto the remote control device via the bidirectional link. A script is loaded via the bidirectional link and is stored in program memory. Once loaded, the script is interpreted by the virtual machine, thereby calling API functionalities provided, and thereby causing the remote control device to have a desired customized function. Providing the virtual machine on all the members of a family of remote control devices allows the same script to run on any remote control device of the family.

Abstract: A compact, register-based, eight-bit virtual machine is realized on a resource-constrained device such as, for example, an IR remote control device. The IR remote control device includes a script interpreter, as well as loader API functionality and API functionality to support communication over a bidirectional link. The functionality of the remote control device is customized by loading either a machine code API routine and/or a script API routine onto the remote control device via the bidirectional link. A script is loaded via the bidirectional link and is stored in program memory. Once loaded, the script is interpreted by the virtual machine, thereby calling API functionalities provided, and thereby causing the remote control device to have a desired customized function. Providing the virtual machine on all the members of a family of remote control devices allows the same script to run on any remote control device of the family.

Abstract: A “call relative counted” script instruction is interpreted by a script interpreter of an eight-bit, register-based, virtual machine. In one embodiment, the script instruction has a first argument field and a second argument field. Interpreting the script instruction causes a jump to a location identified by a label in the first argument field. After a number of script instructions identified by the second argument have been interpreted, the interpreting of script instructions automatically returns to the next script instruction after the call relative counted script instruction. In one example, the first argument is a label, the label in turn identifying the location to jump to. In another example, the first argument directly indicates the location to jump to. The instruction is useful in allowing multiple higher-level scripts to reuse different parts of a common lower-level block of script. The common block performs a common function required by the higher-level scripts.

Abstract: A machine code API can be loaded onto an eight-bit, register-based virtual machine. A higher level script that is interpreted by a script interpreter of the virtual machine can then use the new functionality provided by the added API. The API may, for example, provide access to hardware of the underlying platform that is otherwise inaccessible to a higher level script. The API loading feature sees use where the virtual machine is remotely deployed in the field but can be communicated with via a bidirectional link. The API is communicated to the virtual machine via the bidirectional link and the API is loaded onto the virtual machine. The API is assigned a reference that a higher level script can use to call the API. Using this feature, various APIs can be loaded and their operations tested. Unwanted machine code APIs can also be erased from the virtual machine.

Abstract: A script is stored on a remote control device. When a key is pressed, an interpreter on the remote control device interprets the script thereby causing codeset information (for example, key codes and protocol information) stored on the remote control device to be used to output a sequence of marks and spaces. Adjacent marks are combined into a larger mark and adjacent spaces are combined into a larger space. From these marks and spaces, a mark/space table and a string of timing information are generated. The mark/space table and the string of timing information are then used to generate an operational signal that is transmitted from the remote control device. In one embodiment, only one mark/space table and one string of timing information is ever present on the remote control device at one time. This reduces memory requirements, thereby reducing manufacturing cost of the remote control device.

Abstract: A remote control device detects that a command has been chosen. A command may, for example, have been chosen by a user pressing a key on the remote control device. In response, the remote control device generates a mark/space table and a string of timing information. The string of timing information includes entries that refer to mark time values and space time values in the mark/space table. The string of timing information also may contain special control portions (for example, a control portion can indicate that a portion of the string of timing information should be repeated a given number of times). The mark/space table and the string of timing information are then used to generate an operational signal that is transmitted from the remote control device. The mark/space table and string of timing information is a particularly compact way of describing an operational signal for a remote control device.

Abstract: A security channel is provided for communication with an eight-bit, register-based, virtual machine. The virtual machine is placed into a direct mode, and then individual script instructions are sent to the virtual machine across the security channel for immediate interpreting by the virtual machine. The instructions are interpreted one by one as they are received. This feature can be used in debugging. This feature is usable in applications in which resident code is not required, but rather incoming script instructions are adequate to control device operation. A large memory is not required to store scripts, thereby reducing virtual machine system cost. Script instructions usable in the direct mode include instructions for loading a script API or machine code API onto the virtual machine from an external system, for loading a script, and for causing the virtual machine to output the contents of memory and/or internal registers to the external system.

Abstract: A virtual machine has a first upper level script, a second upper level script, and common block of script. The first and second scripts and the common block of script are interpreted by an interpreter of the virtual machine. The common block of script may, for example, be a script that encodes data bits in accordance with a remote control device communication protocol. The first script may include information for outputting first data bits (for example, key data). The second script may include information for outputting second data bits (for example, key data). The first script calls the common script, thereby outputting the first data in accordance with the protocol. The second script also calls the common script, thereby outputting the second data in accordance with the same protocol. Use of the common script in the outputting of the first and second data reduces memory requirements and therefore system cost.