Method of testing radiation for a SDRAM

A method of irradiating a synchronized dynamic random access memory (SDRAM) by a test device, wherein a status of the SDRAM after a radiation test is determined and calculated, the steps of the method comprising:

• performing a self-test on the test device after starting;
• waiting for a ‘start’ signal from an irradiation controller, the irradiation controller continuously producing periodic radiation, wherein each cycle of the periodic radiation includes on/off regions;
• checking whether the SDRAM is in an off region, wherein no radiation is radiated on the SDRAM, and a test pattern is written from the test device to the SDRAM;
• calculating readings obtained from the SDRAM, and obtaining a difference of the readings;
• checking whether the SDRAM is in an on region, wherein radiation is radiated on the SDRAM, and checking if there is an abnormal current present in the SDRAM, wherein:
• if there is an abnormal current present in the SDRAM, the test device goes back to the self-test step;
• if there is no abnormal current present in the SDRAM, checking whether the SDRAM is in an off region;
• ensuring the SDRAM is in the off region, wherein no radiation is radiated on the SDRAM, and a test pattern is written from the test device to the SDRAM;
• calculating the readings which are obtained from the SDRAM before and after the test, and obtaining a difference of these readings;
• checking whether a ‘stop’ signal is transmitted from the irradiation controller;
• and
• when the irradiation controller does not send out a ‘stop’ signal, returning to the step of writing a test pattern from the test device to the SDRAM, and calculating the readings which are obtained from the SDRAM before and after the test, and obtaining a difference of these readings.