CONSTITUTING MEMORY, DIGITAL SYSTEM, METHOD FOR CONSTITUTING AND PROGRAMMING PROGRAMMABLE LOGIC DEVICE AND METHOD FOR PROGRAMMING CONSTITUTING MEMORY

摘要

PROBLEM TO BE SOLVED: To program a constituting memory in system by allowing a joint test action group(JTAG) circuit to receive one instruction from the group of JTAG instructions from a JTAG port so as to control the operation of the constituting memory. SOLUTION: The instruction register 456 of the JTAG circuit 450 can be loaded only while a TAP controller 454 is in some state. In other states, the JTAG circuit 450 operates according to an instruction within the register 456. By positioning the controller 454 in a proper state and loading a correct instruction within the resistor 456, data is serially scanned within the memory cell of a memorial array 400. Thereby the memorial array 400 can be programmed by constituting data. The programming of the memorial array 400 can be attained also when constituting data is positioned within a system it exists.