The digital input functions with DMA transferring make it possible to retrieve the digital input with high speed. In this mode, the data directly flows from the device port to the memory without the interference of the CPU. The driver will monitor the progress of the acquisition and send the proper event to notify the user of the current acquisition status.
The call flow for digital input with DMA transferring is shown below.
1. Event Notification (Recommended)
Before performing the operation, set the properties by DRV_DeviceSetProperty, such as data width, start/ stop type, clock source, buffer size and etc. The DRV_EnableEvent function enables the notification event and then start the digital output operation by DRV_FDIStart. The driver will send you proper event to notify the status of the acquisition progress. Use DRV_CheckEvent to check the signaled event and then handle the data. Stop the operation by calling DRV_FDIStop function at any time.
2. No Event Notification
Before performing the operation, set the properties by DRV_DeviceSetProperty, such as data width, start/ stop type, clock source, buffer size and etc. The DRV_FDIStart function starts the digital input operation with DMA transferring. Use the DRV_FDICheck function to check the status of the acquisition. Stop the operation by DRV_FDIStop function when the conversion is completed or at any other time. In this type of acquisition, event notification of the acquisition status will not be received. The only way to monitor the acquisition is to call the DRV_FDIheck to check the status of the acquisition progress.
