Abstract
A diagonal test method for flash memory is disclosed in the present invention. In the test method, the flash memory is virtually treated as plural squares; and the test is executed from top to the bottom and from left to the right direction. Each square has the first diagonal line of -45 DEG from left top to the right bottom and the second diagonal line of +45 DEG from left bottom to the right top. In the invention, the device of the first diagonal line or the second diagonal line is programmed. After that, the device excluding that of the first diagonal line or the second diagonal line is read. Alternatively, the device excluding that of the first diagonal line or the second diagonal line is programmed. Then, the device of the first diagonal line or the second diagonal line is read such that the interference fault of the flash memory and the fault of general memory are quickly and effectively detected.