Specifications

30 Cross Bus Interface HighWire MTP-2 - 1.2, September 4, 2002
• Support for multiple MTP3 applications.
• Support for multiple HW400 cards.
4-1-2. HWMTP2 for SDK For the purposes of this document, the system consists of two parts:
• The CBI library, embedded into the hwmtp2_for_sdk.o executable, is a
VxWorks-based counterpart to the CBI library for Solaris. It provides the
same message-passing interface from the target system, without the use
of STREAMS.
• The MTP2 and MTP1 layers themselves, passing target-side messages to
the HDLC controller.
4-2. Using the Cross Bus Interface
Basic interface functions include:
• cbi_initialize—initialize the CBI library (Section 4-2-1)
• cbi_terminate—finish with library (Section 4-2-1)
• cbi_open—open a connection to the line card (Section 4-2-2)
• cbi_close—close connection to the line card (Section 4-2-4)
• cbi_send—send message to an MTP2 instance (Section 4-2-5)
• cbi_recv—receive message from MTP2 instance on line card
(Section 4-2-6)
4-2-1. Initialization and termination Before making any other calls, an application must first initialize the library by
calling cbi_initialize(). When an application has finished using the
library, it must invoke cbi_terminate() before shutting down.
4-2-2. Opening and closing a
connection to a line card
To send messages to and from a line card, an application must first open a
connection to the line card with which it wishes to communicate. This task is
accomplished with the cbi_open() call. The application provides an
appl_correlator to the library, which is returned to the application by all library
callback functions and allows the application to identify the line card
associated with those callbacks. The application supplies the cbi_correlator
returned by cbi_open() as a parameter to all subsequent calls to the
library. When an application no longer wishes to communicate with a specific
line card, it invokes cbi_close().
4-2-3. Opening and closing a sub-
interface
The CBI interface acts as a reliable transport over which different interfaces
may be multiplexed. Within the context of this document, a set of Inter-
Process Signal (IPS) messages composing a single SBE product interface (for
example the interface to MTP2) is referred to as a sub-interface. Each
sub-interface is described in its own header file.