CLOCK FOR SERIAL COMMUNICATION DEVICE

摘要

Versatility and flexibility of integrated circuits can be accomplished by remote control via a serial interface, such as SPI. Read/write accesses to the SPI slave node can be achieved according to SPI protocol by the master node. Additionally, a state machine associated to the slave node SPI needs a local clock to exercise the control of the analog functions following a write access. The serial protocol defines a serial data word transfer to comprise a number of reserved clock cycles that are not assigned for communicating a data bit value of the data word. The slave device comprises a clock unit coupled to the serial clock line for providing a derived clock based on reserved clock cycles. The derived clock is used internally in the slave device to perform internal synchronous operations.