The X25F047 is a CMOS 4K-bit SerialFlash, internally organized as 512 x 8. The X25F047 features a Serial Peripheral Interface (SPI) and software protocol allowing operation on a simple four-wire bus. The bus signals are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled through a chip select (CS) input, allowing any number of devices to share the same bus. There are eight options for programmable, nonvolatile, Block Lock Protection available to the end user. These options are implemented via special instructions programmed to the part. The X25F047 also features a PP pin that can be used for hardwire protection of the part, disabling all programming attempts, as well as a Program Enable Latch that must be set before a program operation can be initiated.