| Dewesoft C++ DLL | Trenz Electronic C++ DLL |
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| HANDLE m_handle = 0; | CCyUSBDevice *USBdevList = new CCyUSBDevice((HANDLE)0,CYUSBDRV_GUID,true); | Tip |
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| The handles are internally managed by CyAPI.lib and there is no need to expose them to the user. |
| Note |
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| CyUSBDevice TE_USB_FX2_USBDevice doesn't explicitly exist in C++, unlike the C# case; this is a shortcoming of CyAPI.lib. d=0; USBdevList->Open(d); // Open automatically calls Close() if necessary vID = USBdevList->VendorID; // not (USBdevList->TE_USB_FX2_USBDevice).VendorID as logically expected pID = USBdevList->ProductID; // not (USBdevList->TE_USB_FX2_USBDevice).ProductID as logically expected |
| | cout << endl << TE0300_ScanCards() << endl; | cout << endl << TE_USB_FX2_ScanCards(USBdevList) << endl; | | TE0300_Open(&m_handle, 0) !=0; | TE_USB_FX2_Open(USBdevList, 0)!=0; | Tip |
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| | In the code, it is possible to call TE_USB_FX2_Open() where TE0300_Open() is used. |
| Note |
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| title | TE_USB_FX2_Open() act as Close() for other TE USB handles already open |
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| When a new handle to the device driver is open (TE_USB_FX2_Open() run successfully) other internal handles (inside USBDeviceList) are automatically closed by TE_USB_FX2_Open() function. No more than one handle can be active on the same time. It is a behavior inherithed by CyAPI.dll Open() function. For this reason, TE_USB_FX2_Close() function is almost useless. d=0; USBdevList->Open(d); // Open automatically calls Close() if necessary (from the Cypress CyAPI documentation)
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| title | TE_USB_FX2_Open() as SelectCard() |
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| | TE_USB_FX2_Open(USBdevList, x) acts more as a SelectCard() function because the list of USB devices is already created in USBdevList. |
| | TE0300_Open(&m_handle, 1)!=0; | TE_USB_FX2_Open(USBdevList, 1)!=0 | | TE0300_Close(&m_handle); | TE_USB_FX2_Close(USBdevList); | Tip |
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This function closes all internal handles of USBDeviceList. This function does NOT differ much from from its homonym of the previous TE0300DLL.dll; the only difference is that this function closes a handle (like TE0300DLL.dll) to the driver but the handle is not exposed to user because it is not exposed by USBDeviceList (unlike TE0300DLL.dll). In the code, it is possible to call TE_USB_FX2_Close() where TE0300_Close() is used, but - it is rare that you would ever need to call TE_USB_FX2_Close() explicitly (though doing so would not cause any problems).
- TE_USB_FX2_Open() realize automatically much of the TE_USB_FX2_Close() work. Close is automatically carried out by the TE_USB_FX2_Open() function, if another handle to the same device driver is already open (i.e. a TE_USB_FX2_Open() has been successfully used before).
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| Note |
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| title | Warning about derived variables |
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| | If TE_USB_FX2_Close() is called, then dynamically allocated members of the CCyUSBDevice class are de-allocated. And, all "shortcut" pointers to elements of the EndPoints array (ControlEndPt, IsocIn/OutEndPt, BulkIn/OutEndPt, InterruptIn/OutEndPt) are reset to NULL. |
| | TE0300_SendCommand(handle, cmd, cmd_length, reply, &reply_length, timeout) | TE_USB_FX2_SendCommand(USBdevList, cmd, cmd_length, reply, reply_length, timeout) | | Equivalent code doesn't exist | TE_USB_FX2_SetData_InstanceDriverBuffer ( USBdevList, &BulkOutEP, PI_EP8, timeout, DeviceDriverBufferSize); | Tip |
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Example: in TE0300DLL.dll, the SET buffer size is fixed to 2 Kbyte, while in TE_USB_FX2_CyAPI.dll you are free to choose 4 Kbyte or more. BufferSize has a strong influence on DataThroughput. If BufferSize is too small, the data throughput can be 1/3 to 1/2 of the maximum value (33-36 Mbyte/s for read transactions). You should instance the driver buffer only one time and not for every transmission, otherwise you could half your data throughput. |
| | Equivalent code doesn't exist | TE_USB_FX2_GetData_InstanceDriverBuffer ( USBdevList, &BulkInEP, PI_EP6, timeout, DeviceDriverBufferSize); | Tip |
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Example: in TE0300DLL.dll, the GET buffer size is fixed to 2 Kbyte, while in TE_USB_FX2_CyAPI.dll you are free to choose 4 Kbyte or more. BufferSize has a strong influence on DataThroughput. If BufferSize is too small, the DataThroughput can be 1/3 to 1/2 of the maximum value (25-28 Mbyte/s for write transactions). You should instance the driver buffer only one time and not for every transmission, otherwise you could half your data throughput. |
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