A trimmable voltage reference uses a flash cell with a variable threshold voltage and a feedback loop to trim a reference voltage. The object of the invention is to implant a power-off debug program and a standby debug program into Basic Input Output system of a computer. Its uses would enhance the work load in building, and in the small lubrication industry, as well as offer a healthier and safer working environment. The control panel, water-level indicator light, cell box, and water pump are coupled to the control circuit. A solder resist layer is formed on the base substrate and a portion of the electrically conductive pattern. The present invention makes it possible to improve the production yield and performance of the semiconductor device having a nonvolatile memory.