Patent ID: 8324930
Filing Date: 2012-12-04
Classification: H03K

Abstract:
1. A method of implementing output ports of a programmable integrated circuit, the method comprising: loading a first set of configuration bits associated with a plurality of output ports, the first set of configuration bits including a control circuit configuration bit associated with a first output port of the plurality of output ports; coupling, by a control circuit in response to the first set of configuration bits; control signals to predetermined output ports of the integrated circuit, the control signals including a first output buffer control signal coupled to the first output port of the plurality of output ports while configuration data is loaded in the integrated circuit, wherein each output port of the plurality of output ports has an output buffer coupled to an output terminal; setting, by the control signals, initial output values of the predetermined output ports during programming of the programmable integrated circuit; and enabling, in response to a second buffer control signal coupled to the output buffer of the first output port after the configuration data is loaded, normal operation of the first output port after the programming of the programmable integrated circuit, wherein setting initial output values of the predetermined output ports comprises setting, for each output port of the predetermined output ports, an initial value of a tri-state buffer control signal coupled to a tri-state buffer of the output port.