28HS01GTAM03 datasheet(45/138 Pages) INFINEON

45 / 138 page

Datasheet

45 of 138

002-18216 Rev. *W

2022-01-18

256Mb/512Mb/1Gb SEMPER™ Flash

Octal interface, 1.8V/3.0V

Features

4.5.2.2

Dynamic DYB (volatile) sector protection

Dynamic Protection Bits (DYB) are volatile and unique for each sector and can be individually modified. DYBs only

control protection for sectors that have their PPBs cleared. By issuing the DYB Write transaction, the DYB are set

to 0 or cleared to 1, thus placing each sector in the protected or unprotected state respectively. This feature

allows software to easily protect sectors against inadvertent changes, yet does not prevent the easy removal of

protection when changes are needed. The DYB can be set to 0 or cleared to 1 as often as needed

In Dynamic Sector Protection scheme, an option is provided to reset all DYB volatile protection bits to '0' upon

power up (protected), essentially protecting all sectors from erase or program. Selecting bit 4 in the Advanced

Sector Protection Register (ASPO[4] - ASPDYB) selects the Dynamic Protection (DYB) for all sectors at power-up

protection scheme. These DYB bits can be individually set to '1', if desired. The Dynamic Sector Protection

scheme flowchart showing power up protection is shown in Figure 47.

Figure 47

Dynamic sector protection scheme flowchart

4.5.2.3

Permanent/temporary PPB (nonvolatile) sector protection

Each nonvolatile bit (PPB) provides nonvolatile protection for an individual memory sector, which remains

locked (protection enabled) until its corresponding bit is cleared to 1. There are two options to control the PPB

based nonvolatile selection in ASP, namely Permanent and Temporary.

4.5.2.4

Permanent PPB protection scheme

The PPB are located in a separate nonvolatile flash array. One of the PPB bits is assigned to each sector. When a

PPB is programmed to 0 its related sector is protected from program and erase operations. The PPB are

programmed individually but must be erased as a group, similar to the way individual words may be programmed

in the main array but an entire PPB sector must be erased at the same time. Programming a PPB bit requires the

typical word programming time. During a PPB bit programming operation or PPB bit erasing, the Status Register

can be accessed to determine when the operation has completed. Erasing all the PPBs requires typical sector

erase time.

Permanent PPB based protection scheme, as the name applies, is permanent and can never be altered. Once the

PPB architecture is decided, selecting bit 0 in Advanced Sector Protection Register (ASPO[0]) enables the

Permanent Protection for all PPB bits essentially disabling all PPB erase and program operations. ASPO is also

protected from write or program.

The Permanent PPB Protection scheme flowchart is shown in Figure 48.

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