The VCCO supply is the primary power supply of the I/O circuitry. The VCCO (V) columns in Table: VCCO and VREF Requirements for Each Supported I/O Standard provide the VCCO requirements for each of the supported I/O standards, and illustrate the VCCO requirements for inputs and outputs as well as the optional internal differential termination circuit.
All VCCO pins for a given HP I/O bank must be connected to the same external voltage supply on the board, and as a result, all of the I/O within a given I/O bank must share the same VCCO level. The VCCO voltage must match the requirements for the I/O standards that have been assigned to the I/O bank.
CAUTION! Incorrect VCCO voltages can result in loss of functionality or damage the device.
In HR I/O banks, if the I/O standard voltage requirement is £1.8V, but a VCCO voltage of ³2.5V is applied, the device automatically enters an over-voltage protection mode. Reconfiguring the device with the correct VCCO voltage level restores normal operation.