m35b32 STMicroelectronics, m35b32 Datasheet - Page 25

• Manufacturer Part Number: m35b32
• Description: 32 Kbit, 256-byte Page, Fast Program Eeprom Memory Accessed By Spi Bus Interface
• Manufacturer: STMicroelectronics

M35B32
6.8
Note:
Page Program (PP)
The Page Program instruction has be used when addressing erased bytes (see
below).
The Page Program (PP) instruction allows bytes to be programmed in the memory
(changing bits from 1 to 0, only). Before it can be accepted, a Write Enable (WREN)
instruction must have been previously executed. (This sets the Write Enable Latch (WEL)
bit).
The Page Program (PP) instruction is entered by driving Chip Select (S) low, followed by the
instruction code, two address bytes and at least one data byte on Serial Data Input (D). The
transmitted data must NOT exceed the addressed page boundary as a wrap round would
corrupt the data from the start address of the same page. Chip Select (S) must be driven
low for the entire duration of the sequence.
The instruction sequence is shown in
Chip Select (S) must be driven high after the eighth bit of the last data byte has been latched
in, otherwise the Page Program (PP) instruction is not executed.
As soon as Chip Select (S) is driven high, the self-timed Page Program cycle is initiated.
The Page Program cycle lasts t
sector is addressed. While the Page Program 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 Program cycle, and it is at 0 when the cycle is
completed. The Write Enable Latch (WEL) bit is also reset (or not) once the self-timed Page
Program cycle is complete, depending on the logical level applied on the W input pin and the
value of the decoded address, as shown in
A Page Program (PP) instruction applied to a page that is Hardware Protected is not
executed.
Any Page Program (PP) instruction, while an Erase, Program or Write cycle is in progress, is
rejected without having any effects on the cycle that is in progress.
The Program instruction does not include an Erase cycle (unlike the Page Write instruction,
which includes two cycles: Erase+ Program). As a consequence, the Page Program
instruction has to be used only when pointing to locations which were previously erased.
In addition, as the M35B32 offers the ECC feature (see
before programming data with the Page Program instruction, that the addressed bytes are
inside an erased area defined as a multiple of four bytes.
Example: to program data inside locations [003h-011h], the minimum erased area has to be
[000h-013h], because location 003h belongs to the four bytes [000h-003h] and location
011h belongs to the four bytes [010h-013h].
Doc ID 18391 Rev 3
PP
when the Data sector is addressed, or t
Figure
Table
14.
4.
Section
6.9), it is important to check,
FP
when the Event
Instructions
Note:
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