摘要:
Circuitry is implemented within an integrated circuit ("chip") (101) which is an IEEE 1149.1 compliant device capable of performing JTAG testing (104), such as an EXTEST or CLAMP testing procedure. Upon exiting of either of these procedures, the input/output pins (210) of the chip are placed in a known state, which may be a high impedance state.
摘要:
In a data processor having an instruction which requires the loading of the contents of two (2) successive locations in the address space during respective bus cycles, test circuitry is provided to selectively force the processor to twice load the contents of the same location upon execution of the instruction. Using this special load double test instruction, the processor is able to detect more precisely when the contents of the memory location changes in value as a result of the activity of other circuitry.