The invention provides a method for serial data transmission. First, a chip select signal is enabled to a device for serial data transmission. Data stored in a first buffer of a controller is then transmitted to a second buffer of the device. A clock signal is then halted after data stored in the first buffer is completely transmitted. The first buffer is then refreshed with data newly received by the controller while the clock signal is halted. The clock signal is the restarted to operate the device after the first buffer is refreshed. Refreshed data stored in the first buffer is then transmitted to the second buffer while the clock signal is oscillating.