| 摘要 |
A boundary scanning method is provided to facilitate a memory test process by coping with various package options by determining whether to test a boundary scan cell, before an actual test process. A semiconductor device is tested under various package options by using a boundary scan control signal. After a bypass instruction or an ID code instruction is performed, a package selection instruction is selected to determine whether to perform bypass according to a control signal of an instruction register of a tap controller. A flag bit for determining whether to use a corresponding boundary scan register cell is allocated. The allocated bits are shifted according to the control signals from respective registers, when the logic level of the control signal is 1. Whether to bypass a corresponding boundary scan register cell is determined, so that the boundary scan process is updated. After other instructions are loaded, the boundary scan process is performed.
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