() ()

# [TEMPERATURE ERRATA](#TEMPERATURE_ERRATA)

There are a group of obscure internal properties exposed to protect against an hardware defect in certain batches of the B7 die of some DS18x20 chips. See http://www.1wire.org/en-us/pg\_18.html or request AN247.pdf from Dallas directly.

## [errata/die](#errata/die)

*read-only,ascii*  
Two character manufacturing die lot. "B6" "B7" or "C2"

## [errata/trim](#errata/trim)

*read-write,unsigned integer*  
32 bit trim value in the EEPROM of the chip. When written, it does not seem to read back. Used for a production problem in the B7 *die.*

Read allowed for all chips. Only the B7 chips can be written.

## [errata/trimblanket](#errata/trimblanket)

*read-write,yes-no*  
Writing non-zero (=1) puts a default trim value in the chip. Only applied to the B7 *die.* Reading will be true (non-zero) if trim value is the blanket value. Again, only B7 chips will register true, and since the written trim values cannot be read, this value may have little utility.

## [errata/trimvalid](#errata/trimvalid)

*read-only,yes-no*  
Is the *trim* value in the valid range? Non-zero if true, which includes all non-B7 chips.

---

Document: temperature_errata(3so) from owfs 3.2.4-r8 (Chainguard OS)
Source: https://github.com/owfs/owfs