ACE25C200

2MB Serial Flash Memory

VER 1.2

17

Figure 13 Fast read dual I/O instruction (previous instruction set M5-4=10)

Page Program (02h)

The Page Program instruction allows from one byte to 256 bytes (a page) of data to be programmed

at previously erased (FFh) memory locations. A Write Enable instruction must be executed before the

device will accept the Page Program Instruction (Status Register bit WEL= 1). The instruction is

initiated by driving the CS# pin low then shifting the instruction code “02h” followed by a 24-bit

address A23-A0 and at least one data byte, into the DI pin. The CS# pin must be held low for the

entire length of the instruction while data is being sent to the device. The Page Program instruction

sequence is shown in Figure 14.

If an entire 256 byte page is to be programmed, the last address byte (the 8 least significant address

bits) should be set to 0. If the last address byte is not zero, and the number of clocks exceeds the

remaining page length, the addressing will wrap to the beginning of the page. In some cases, less

than 256 bytes (a partial page) can be programmed without having any effect on other bytes within the

same page. One condition to perform a partial page program is that the number of clocks can not

exceed the remaining page length. If more than 256 bytes are sent to the device the addressing will

wrap to the beginning of the page and overwrite previously sent data.