5.53 Page Program_4Byte (PP_4Byte)

The Page Program_4Byte instruction programs up to 256 bytes of data into memory and supports both SPI and QPI protocols. Before initiating the Page Program_4Byte operation, the selected page address must be in the erased state (FFH). If the instruction is applied to a protected memory region, the operation is ignored. The WREN instruction must be executed prior to issuing the Page Program_4Byte command.

To execute a Page Program_4Byte operation, the host drives CE# low, issues the command cycle (12H) in SPI or QPI mode, transmits four address bytes followed by the data to be programmed, and then drives CE# high. The programmed data length must be between 1 and 256 bytes in whole-byte increments. Any partial byte transmitted is ignored. Completion of the internally timed Page Program operation can be verified by polling the Busy bit in Status Register 1 or by waiting for the specified T_PP interval.

During a Page Program_4Byte operation, memory is organized into 256-byte page boundaries. If more than 256 bytes of data are transmitted, only the last 256 bytes received are retained and programmed. If the target address is not aligned to a page boundary (A[7:0] are not all zero) and the transmitted data exceeds the remaining space in the page, the excess data wraps around and is programmed at the beginning of the same target page.