Technology for asynchronous communication including a wired channel, a sender controller, and a receiver controller is disclosed. The sender controller can be configured to send multiple request signals up to a predefined limit on the output request port paired with multiple data blocks sent on the data before receiving an acknowledgment signal on the output acknowledge port. At least one combination of any of the input channel, the sender controller, the output channel, and the receiver controller can be configured to operate within at least one time constraint to avoid stalling an asynchronous flow control.