Elan Microelectronics Corporation

Chun-An Tang

Yen-Chang Chiu

Cheng-Hao Tang

Kuang-Yeu Lin

Chun-Chi Wang

Tsung-Yin Chiang

Po-Hao Wu

A circuit and method for trimming an internal oscillator of a USB device that generates a clock signal as a frequency source of the USB device detect an end of packet from an input data stream to initialize a counter, identify a token packet in the data stream to detect a start of frame token packet for the counter to carry out clock counting on the clock signal to thereby obtain a count value, and compare the count value with a reference value to determine a trimming code for trimming a clock frequency of the internal oscillator.

Method and circuit for trimming an internal oscillator of a USB device according to a counting number between a first and second clock count value

An on-system programmable and off-system programmable chip comprises a control circuit connected to an on-system programmable nonvolatile memory and an off-system programmable nonvolatile memory, and a pumping circuit connected to the on-system programmable nonvolatile memory. In a programming mode of the chip, external programming voltages are provided for programming the off-system programmable nonvolatile memory, and in an operation mode of the chip, the pumping circuit produces internal programming voltages for the on-system programmable nonvolatile memory for programming the on-system programmable nonvolatile memory.

On-system programmable and off-system programmable chip

Growing community of inventors

Baoshan, China

Chun-An Tang