eMorpho API

Author:

Bridgeport Instruments, LLC

Date:

2005 - 2011

Overview

Hierarchy

The API consists of a hierarchical set of four layers.

libusb and libftdi (libusb.lib, ftdi.obj)

The code uses the libftdi driver built on libusb. These open-source codes provide the most accurate control over the communication with the FT245RL usb-controller. For libusb-win32 see http://www.libusb.org/wiki/libusb-win32. For libftdi visit intra2net at http://www.intra2net.com/en/developer/libftdi/.

OS and driver-dependent I/O

The second layer consists of functions to communicate with the hardware and a wrapper, called Morpho_IO through which all communications attempts from higher level functions are routed (BPI_Morpho_Low.c). All functions that use Morpho_IO are written in an operating system independent manner. We do, however, stick to the convention that the least significant byte or word is written and read first.

Direct access to hardware/firmware registers

An intermediate layer provides easy to use read and write functions for direct access to the various back-end modules inside the FPGA (BPI_Morpho_Mid.c). The file BPI_Morpho_registers.c contains functions that provide access to the bit-fields in the 16 control registers of the eMorpho. Using these functions isolates the application from a future change of the contents of the control registers.

Compex functions

The top layer of the API comprises functions to operate the Morpho detector and convert all the information stored in the data acquisition board into physical quantities (BPI_Morpho_High.c).

Unified command interface

A unified command interface provides a convenient, but optional, common entry point for all Morpho commands (BPI_Morpho_Functions.c). Its single function, MorphoCommand() also loads and manages the USB driver DLL.

Examples

In a typical application, programmers use only the high-level functions and some of the data read functions from the mid-level. A few stand-alone examples, coded in C, have been included in BPI_Morpho_Examples.c.

Data types

The API has been written to use 32-bit integers as the default integer size and double's as the default floating point format, because C performs all floating-point computations in double precision. The types long and unsigned long have been redefined as int32 and uint32 to show more clearly the intended size.