SPRADL4 January 2025 F29H850TU , F29H859TU-Q1
To support EEPROM emulation with varying data sizes (greater than 64 bits), the Flash sectors selected for emulation are divided into a format referred to as EEPROM Banks (not to be confused with Flash Banks) and Pages. This aspect of the emulation is the same for both the Single-Unit and Ping-Pong implementations.
The flash sector(s) chosen for emulation are subdivided into EEPROM banks, which are in turn divided into Pages. This is depicted in Figure 3-3.
Using this format allows the application to:
Figure 3-3 Bank PartitioningThe application tracks which bank and page is in use through status codes. For more information, seeSection 5.2.2.1.
To track which EEPROM banks are empty, current, or full the first 16 bytes (128 bits) of each bank are reserved. On switching to a new bank, the status of both the previous and new EEPROM banks is updated to reflect the new state.
Pages are handled in a similar manner: the first 16 bytes (128 bits) of each page is reserved to determine if it is empty, current, or used. Whenever new data is written to a Page, the status of both the previous and new Pages is updated.
To mark an EEPROM Bank or Page as current, the first 64 bits are written with the appropriate status code. To mark an EEPROM Bank or Page as full, the second 64 bits are written with the appropriate status code.
As seen in Page Layout, all pages contain an eight-word page status and a configurable amount of data space. Page 0 is slightly different as it contains the EEPROM bank status as well. Although only Pages 0 and 1 are shown, it should be noted that Page 2 through Page (N-1) are identical to Page 1.
Figure 3-4 Page Layout