Apparatus for developing internal ROM code using a ROM bus external interface

摘要

An apparatus for developing internal ROM code is disclosed for use in applications where software code is being developed for a ROM device inside a device and there is a need for the application to cause code from an external memory to be executed at the same time as internal ROM code. Accessing code from an external memory requires the use of the external bus interface. In order to free the external memory for use and the external bus interface for accessing code from external memory yet still allow testing of ROM code from an external memory before it is implemented on a ROM chip inside the device, an additional memory is used outside the device, and internal control logic is added.