摘要 |
A method and a system for reprogramming a closed device are disclosed. In one embodiment, the system contains an external memory coupled to a limited access device. The limited access device includes a processor, an internal memory, a select control circuit, an internal data bus, and an external data bus. The internal memory is not accessible except through predefined input and output ports of the select control circuit, which are accessible external to the closed device. The select control circuit selects the external memory as primary memory in response to assertion of a control signal and selects the internal memory as primary memory in response to deassertion of a control signal. The internal data bus transports data within the limited access device which includes the internal memory and the select control circuit and the external data bus transports data between the select control circuit and the external memory.
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