Device for use in developing and testing a one-chip microcomputer

Claim 1

A universal package for a microcomputer chip detachably mounted on a microcomputer chip final product board for selectively and detachably connecting said microcomputer chip to testing means or to a rewriteable read-only memory, said testing means being used at an early stage to check operation of said microcomputer chip and said rewriteable read-only memory being used at a later stage in developing and evaluating a program stored in a permanent read-only memory to be permanently connected to said microcomputer chip final product board, said package comprising: a plurality of testing terminals for connection selectively to said testing means and to said rewriteable read-only memory during successive stages of checking the operation of the microcomputer chip and the evaluation of said program presently in the microcomputer chip and to be subsequently stored in said permanent read-only memory; and switching means connected to said plurality of testing terminals, for establishing a first internal electrical configuration in which a first set of said testing terminals are activated when said rewriteable read-only memory is connected to said testing terminals and a second internal electrical configuration in which a second set of said testing terminals are activated when said testing means is connected to said testing terminals, said first and second sets of activated terminals being different; wherein said switching means comprises an input terminal and means responsive to a signal applied to said input terminal, said responsive means being constructed so that when said signal has a first value said responsive means establishes said first internal electrical configuration and when said signal has a second value said responsive means establishes said second internal electrical configuration.