ACE25C200

2MB Serial Flash Memory

VER 1.2

18

As with the write and erase instructions, the CS# pin must be driven high after the eighth bit o f the

last byte has been latched. If this is not done the Page Program instruction will not be executed. After

(See “12.6 AC Electrical Characteristics”). While the Page Program cycle is in progress, the Read

Status Register instruction may still be accessed for checking the status of the WIP bit. The WIP bit is

a 1 during the Page Program cycle and becomes a 0 when the cycle is finished and the device is

ready to accept other instructions again. After the Page Program cycle has finished the Write Enable

Latch (WEL) bit in the Status Register is cleared to 0. The Page Program instruction will not be

executed if the addressed page is protected by the Block Protect (BP2, BP1, and BP0) bits.

Figure 14 Page program instruction

Sector Erase (20h)

The Sector Erase instruction sets all memory within a specified sector (4K -bytes) to the erased state

of all 1s (FFh). A Write Enable instruction must be executed before the device will accept the Sector

Erase Instruction (Status Register bit WEL must equal 1). The instruction is initiated by driving the

CS# pin low and shifting the instruction code “20h” followed a 24-bit sector address A23-A0 (see

Figure 1). The Sector Erase instruction sequence is shown in Figure 15 .

The CS# pin must be

driven high after the eighth bit of the last byte has been latched. If this is not

done the Sector Erase instruction will not be executed. After CS# is driven high, the s elf-timed

Characteristics”). While the Sector Erase cycle is in progress, the Read Status Register instruction

may still be accessed for checking the status of the W IP bit. The WIP bit is a 1 during the Sector Erase

cycle and becomes a 0 when the cycle is finished and the device is ready to accept other instructions

again. After the Sector Erase cycle has finished the Write Enable Latch (WEL) bit in the Status

Register is cleared to 0.

The Sector Erase instruction will not be executed if the addressed page is protected by the Block

Protect (BP2, BP1, and BP0) bits (see Table 2 Status Register Memory Protection table).