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ACE25C400 Datasheet, PDF (11/31 Pages) ACE Technology Co., LTD. – 4MB Serial Flash Memory
ACE25C400
4MB Serial Flash Memory
3. At least one byte of data input is required for Page Program and Program Security Sectors, up to 512 bytes of data input. If
more than 256 bytes of data are sent to the device, the addressing will wrap to the beginning of the page and overwrite
previously sent data.
4. See Table 3 Manufacturer and Device Identification table for device ID information.
5. Dual SPI address input format:
DQ0 = A22, A20, A18, A16, A14, A12, A10, A8 A6, A4, A2, A0, M6, M4, M2, M0
DQ1 = A23, A21, A19, A17, A15, A13, A11, A9 A7, A5, A3, A1, M7, M5, M3, M1
6. Dual SPI data output format: DQ0 = (D6, D4, D2, D0) DQ1 = (D7, D5, D3, D1)
Write Enable (WREN) (06h)
The Write Enable (WREN) instruction (Figure 5) sets the Write Enable Latch (WEL) bit in the Status
Register to a 1. The WEL bit must be set prior to every Page Program, Sector Erase, Block Eras e,
Chip Erase, Write Status Register instruction. The Write Enable (WREN) instruction is entered by
driving CS# low, shifting the instruction code “06h” into the Data Input (DI) pin on the rising edge of
CLK, and then driving CS# high.
Figure 5 Write enable instruction
Write disable (WRDI) (04h)
The Write Disable (WRDI) instruction (Figure 6) resets the Write Enable Latch (WEL) bit in the Status
Register to a 0. The Write Disable (WRDI) instruction is entered by driving CS# low, shi fting the
instruction code “04h” into the DI pin and then driving CS# high. Note that the WEL bit is automatically
reset after Power-up and upon completion of the Write Status Register, Page Program, Sector Erase,
Block Erase, Chip Erase instructions.
Figure 6 Write disable instruction
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