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

2.3 Typical Communication Flow on the 1-Wire Bus

GUID-FB7CCB57-E0C3-4BBD-9687-5A4E402C4395-low.gif Figure 2-6 Typical Communication Flow on a 1-Wire Bus
  • Start with the Reset Sequence
  • If the host must determine which target devices are present on the bus, it should perform a search to detect the 64-bit device address of the devices.
  • Before performing an operation on a device, the device must be configured and/or selected using the ROM commands. Some of the available functional ROM commands are:
    • Read Address [0x33]: Only used when there is a single device on the bus. This command reads the 64-bit device address of the only device present on the bus.
    • Match Address [0x55]: This command followed by a 64-bit device address selects the device with the matching address. All other devices wait until the next reset pulse.
    • Search Address [0xF0]: This command is required to obtain the 64-bit device address of multiple devices, and it informs devices that a search is going to be conducted by the host. The Search is then conducted by reading a bit and its complement of the ROM numbers from the devices and sending an appropriate bit back. For more details, see the Section 4. Target devices that have the same bit as the one sent by the host remain active while others wait for the next reset
    • Skip Address [0xCC]: Devices can be addressed without the host knowing the 64-bit device address. This command is helpful when giving a common command to all the devices.
    • Overdrive Skip Address [0x3C]: This command is used only in single drop. This command is the same as the Skip Address command except that only devices that can run in overdrive mode remain active and go into overdrive mode. Devices that cannot run in overdrive mode wait for the next reset.
    • Overdrive Match Address [0x69]: This command is the same as the Match Address command except that the device is only matched if it can run in overdrive mode. All other devices wait for the next reset.
  • After selecting the required devices, a device-specific command can be issued to perform the required operation.
  • Typically after each operation, a reset pulse is issued.