M35B32 datasheet(27/44 Pages) STMICROELECTRONICS

27 / 44 page

DocID18391 Rev 4

27/44

M35B32

Instructions

6.10

Page Erase (PE)

The Page Erase (PE) instruction is mostly dedicated to the Event sector, as this sector must

be erased before executing a Page Program instruction (fast programming time).

The Page Erase instruction resets to 1 (FFh) all bits inside the chosen page. Before it can

be accepted, a Write Enable (WREN) instruction must have been executed previously. After

the Write Enable (WREN) instruction has been decoded, the device sets the Write Enable

Latch (WEL).

The Page Erase (PE) instruction is entered by driving Chip Select (S) low, followed by the

instruction code, and two address bytes on Serial Data Input (D). Any address inside the

Page is a valid address for the Page Erase (PE) instruction. Chip Select (S) must be driven

low for the entire duration of the sequence.

The instruction sequence is shown in Figure 15.

Chip Select (S) must be driven high after the eighth bit of the last address byte has been

latched in, otherwise the Page Erase (PE) instruction is not executed. As soon as Chip

Select (S) is driven high, the self-timed Page Erase cycle (whose duration is tPE) is initiated.

While the Page Erase cycle is in progress, the Status Register may be read to check the

value of the Write In Progress (WIP) bit. The Write In Progress (WIP) bit is at 1 during the

self-timed Page Erase cycle, and it is at 0 when the cycle is complete. The Write Enable

Latch (WEL) bit is also reset (or not) once the self-timed Page Earse cycle is complete,

depending on the logical level applied on the W input pin and the value of the decoded

address, as shown in Table 4).

A Page Erase (PE) instruction applied to a page in Event sector that is Hardware Protected

is not executed.

Any Page Erase (PE) instruction, while an Erase, Program or Write cycle is in progress, is

rejected without having any effects on the cycle that is in progress.

Figure 15. Page Erase (PE) instruction sequence

3. Address bits A15 to A12 are Don’t Care.

16-bit address

AI15475

3456789

29 30 31

Instruction

15 14

MSB

M35B32 데이터시트(PDF) 27 Page - STMicroelectronics