Data processing apparatus and method for controlling a transfer of payload data over a communication channel

Abstract

A data processing apparatus has initiator circuitry for initiating a transfer of payload data in a first clock cycle, and recipient circuitry for receiving the payload data in a later clock cycle. A communication channel carries the payload data along with associated transfer control information. Timing of receipt of the payload data by the recipient circuitry is controlled by the transfer control information. Timing easing circuitry located within the communication channel temporarily buffers the transfer control information before outputting it to the recipient circuitry. The timing easing circuitry is responsive to a specified timing easing value to determine a time for which the transfer control information is temporarily buffered. The number of clock cycles that elapses between the first clock cycle and the later clock cycle depends on the specified timing easing value. This enables a multi-cycle path to be provided to transfer the payload data.