SPMA057D January   2018  – June 2022 TM4C1290NCPDT , TM4C1290NCPDT , TM4C1290NCZAD , TM4C1290NCZAD , TM4C1292NCPDT , TM4C1292NCPDT , TM4C1292NCZAD , TM4C1292NCZAD , TM4C1294KCPDT , TM4C1294KCPDT , TM4C1294NCPDT , TM4C1294NCPDT , TM4C1294NCZAD , TM4C1294NCZAD , TM4C1297NCZAD , TM4C1297NCZAD , TM4C1299KCZAD , TM4C1299KCZAD , TM4C1299NCZAD , TM4C1299NCZAD , TM4C129CNCPDT , TM4C129CNCPDT , TM4C129CNCZAD , TM4C129CNCZAD , TM4C129DNCPDT , TM4C129DNCPDT , TM4C129DNCZAD , TM4C129DNCZAD , TM4C129EKCPDT , TM4C129EKCPDT , TM4C129ENCPDT , TM4C129ENCPDT , TM4C129ENCZAD , TM4C129ENCZAD , TM4C129LNCZAD , TM4C129LNCZAD , TM4C129XKCZAD , TM4C129XKCZAD , TM4C129XNCZAD , TM4C129XNCZAD , TMP1826 , TMP1826 , TMP1827 , TMP1827

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction to 1-Wire
    1. 1.1 Bus Requirements
    2. 1.2 Powering
  4. 2Functional Description
    1. 2.1 Signaling on 1-Wire
    2. 2.2 Address Format of the 1-Wire Device
    3. 2.3 Typical Communication Flow on the 1-Wire Bus
  5. 3Functions Available in TivaWare for C Series for 1-Wire Module
  6. 4Enumeration
    1. 4.1 Legacy Search Algorithm
      1. 4.1.1 Steps of the 3-Bit Search Algorithm
    2. 4.2 Fast Search Algorithm
  7. 5Summary
  8. 6References
  9. 7Revision History

1.1 Bus Requirements

Every output pin must be open-drain, and a weak pull up must be attached to the signal so that, the bus is driven low if at least one device drives the bus low. This protocol enables the transfer of data between two devices on the bus while the other devices are in the idle state. The strength of the pull up can be decided by the user based on the following factors:

  • The device being externally powered may have pull up values in the range of 10K or more if data rate is not required to be high and trace length on the system is not high.
  • The device being externally powered may have pull up values less than 1K if the data rate is high especially in the overdrive mode or the trace lengths on the system are longer.
  • The device being parasitically powered may require active drivers after being selected so that the end device can have sufficient energy to perform the end operation.