Primary Control Board

When the control board server running on the SSP connects to the CBE running on a control board, the CBE asserts the control board as the primary control board. The primary control board is responsible for the JTAG interface, which enables control board components to communicate with other Sun Enterprise 10000 system components so that the Sun Enterprise 10000 system can be monitored and configured. The primary control board also provides the system clock, which synchronizes and controls the speed of the centerplane, CPU clock, and system boards.