A mechanism is provided for sharing a communication used by a parser (parser path) in a network adapter of a network processor for sending requests for a process to be executed by an external coprocessor. The parser path is shared by processors of the network processor (software path) to send requests to the external processor. The mechanism uses for the software path a request mailbox comprising a control address and a data field accessed by MMIO for sending two types of messages, one message type to read or write resources and one message type to trigger an external process in the coprocessor and a response mailbox for receiving response from the external coprocessor comprising a data field and a flag field. The other processors of the network poll the flag until set and get the coprocessor result in the data field.