SWRA749 September   2022

 

  1.   Abstract
  2.   Trademarks
  3. 1Device Power Up
    1. 1.1 Required Voltage Rail and Signal Sequence
    2. 1.2 nSHUTDOWN and HCI_RTS
  4. 2UART Communication
  5. 3Device Initialization Procedure
  6. 4Basic Bluetooth Operations
  7. 5Bluetooth RF FCC Modes
    1. 5.1 Continuous TX
    2. 5.2 Packet RX TX
    3. 5.3 Continuous RX
  8. 6Bluetooth RF SIG Mode
  9. 7Bluetooth Low Energy Testing
    1. 7.1 Transmitter Test
    2. 7.2 Receiver Test
  10. 8Revision History

1.1 Required Voltage Rail and Signal Sequence

Proper power up of the device:

  1. nSHUTDOWN must be low.
  2. Turn on power supplies:
    1. Turn on VDD_IN (3.3V, max range is 1.8V to 4.8V)
    2. Turn on VDD_IO (1.8V, max range is 1.62V to 1.92V)
    3. VDD_IO and VDD_IN must be stable before releasing nSHUTDOWN.
  3. Slow Clock must be stable within 2ms of releasing nSHUTDOWN.
  4. Fast Clock must be stable within 20ms of releasing nSHUTDOWN.
  5. The CC256x device will indicate a complete proper power-up sequence by pulling HCI_RTS low.
GUID-20220726-SS0I-JVQH-GDPR-FSRNVMHVZTKG-low.jpg Figure 1-1 Proper Power Up Sequence

No signals are allowed on the I/O pins if VDD_IO power is not present. The only exceptions on this are the SLOW_CLK, XTALP, XTALM, and AUD_xxx pins that are fail-safe and can tolerate external voltages without VDD_IO and VDD_IN present.