11.2.17 32KB Block Erase (52h)
The Block Erase instruction sets all memory within a specified block (32k-bytes) to the erased state
of all 1s (FFh). A Write Enable instruction must be executed before the device will accept the Block
Erase Instruction (Status Register bit WEL must equal 1). The instruction is initiated by driving the
/CS pin low and shifting the instruction code “52h” followed a 24-bit block address (A23-A0). The
Block Erase instruction sequence is shown in figure 17.
The /CS pin must be driven high after the eighth bit of the last byte has been latched. If this is not
done the Block Erase instruction will not be executed. After /CS is driven high, the self-timed Block
Erase instruction will commence for a time duration of tBE1 (See AC Characteristics). While the
Block Erase cycle is in progress, the Read Status Register instruction may still be accessed for
checking the status of the BUSY bit. The BUSY bit is a 1 during the Block 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 Status Register is
cleared to 0.The Block Erase instruction will not be executed if the addressed page is protected by
the Block Protect (SEC, TB, BP2, BP1, and BP0) bits (see Status Register Memory Protection
Figure 17. 32KB Block Erase Instruction Sequence Diagram