Controls which clock source will be used to run the main stream clock. 0 = Internal crystal, 2 = External clock, 4 = Primary ESS, 8 = Secondary ESS

• Data type: UINT32  (type index = 1)
• Readable and writable
• Default value: 0
• T8:
  • T8 will expect external stream clock on FIO2.
  • Minimum firmware version: 1.0000
• T7:
  • T7 will expect external stream clock on CIO3.
  • Minimum firmware version: 1.0110