AS29F040-120TC / Alliance Semiconductor Corporation

AS29F040-120TC Datasheet with Chat AI

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Part No.	AS29F040-120TC
Manufacturer	ALSC
Size	341 Kbytes
Pages	18 pages
Description	5V 512K x 8 CMOS FLASH EEPROM

Datasheet Summary with AI

1. General Overview & Key Features

️· Type: Flash memory chip.
️· Functionality: Allows for byte-by-byte programming, sector erasing, and chip erasing.
️· No CPU Control Required: Much of the programming/erasing process is handled internally, reducing CPU overhead.
️· Data Polling: Allows the CPU to monitor the progress of programming/erasing operations.

2. Sector/Chip Erase Details

️· Sector Erase:
- Requires a 6-cycle process: two unlock write cycles, a setup command, two additional unlock write cycles, and the sector erase command (30h).
- The sector to be erased is identified by the address latched during the process.
- Multiple sectors can be erased sequentially, but timing is crucial – writes between sectors must be within 80 µs.
- The chip automatically programs all sectors with 0s before erasing.
- Can be interrupted by a falling edge on WE and must be restarted.
️· Chip Erase:
- Also a 6-cycle process.
- Erases the entire memory array, programming all cells to 0.

3. Programming Details

️· Byte-by-Byte Programming: Programming occurs byte-by-byte.
️· Unlock Write Cycles: Two unlock write cycles precede programming.
️· Data Polling: DQ7 and DQ6 are used for data polling to monitor the status of the programming process. DQ5 goes high if the programming time limit is exceeded.
️· Programming 0s to 1s: Requires an erase operation due to the chip's architecture.

4. Write Protection

️· Verification: Write protection status of sectors is verified by reading address XXX02h. A '1' on DQ0 indicates a protected sector, and a '0' indicates an unprotected sector.

5. Command Sequence (General)

️· The datasheet has multiple 6-cycle command sequences for erase.

Key Terminology

️· WE (Write Enable): A signal used to trigger commands.
️· CE (Chip Enable): A signal that enables the chip.
️· DQ (Data Queue): The data lines for reading and writing.
️· DQ0-DQ7: Specific data lines used for polling and status.
️· XXX00h, XXX01h, XXX02h: Specific memory addresses used for retrieving MFG code, device code and write protection status respectively.