Parity prediction circuitry for a multifunction register

Circuitry for predicting parity for a multifunction register having control inputs for receiving control signals that select the function of said register, said circuitry comprising:

• a parity prediction circuit associated with each function performed by said register and having an output for providing a predicted parity for that function;
• and
• a multiplexer having a plurality of data inputs, each of the data inputs for receiving the predicted parity from the output of one said parity prediction circuit, and control inputs for receiving the control signals that select the function of said register, and a data output for providing the predicted parity selected from one of the data inputs in response to the control signals.

In a data processing system having a register for performing any selected one of a plurality of functions such as COUNT, SHIFT, LOAD, and COMPLEMENT, prediction circuitry for predicting the parity for the data stored in said register, comprising:

• circuit means associated with each function for providing predicted parity of the data stored in aid register when that function is performed;
• and
• selecting means connected for receiving control signals that select the function of said register and in response providing the predicted parity by selecting said circuit means associated with the selected one of the functions to provide its predicted parity.

In a data processing system having a register for storing data and operating as a binary counter and having prediction circuitry for predicting the parity of the next count of the register, the improvement wherein said prediction circuitry comprises:

• a multiplexer having control inputs connected to receive the data stored in said register, data inputs, and a data output, each data input connected to receive a signal at a predetermined logic level, so that in response to the data stored in said register said multiplexer passes one of the signals at its data inputs to its data output as a parity predicting signal.