Interrupt Transferring

There are two kinds of interrupt operations for analog input.

One generates a hardware interrupt for each conversion.

The other one keeps the conversion data in FIFO, then generates a hardware interrupt for a half-full FIFO or full FIFO depending on the hardware. The driver will catch these interrupts. Various events will occur to notify the user of the acquisition status.

Similar to the software transferring, this type of transferring also provides two kinds of functions. One is for single channel reading, the other is for multiple- channel reading.

The following pictures show the typical function call flow for single channel reading.

1. Event Notification (Recommended)

The DRV_EnableEvent function enables the notification event and then starts the analog input operation by DRV_FAIIntStart. The driver will send a proper event to notify the status of the acquisition progress. DRV_CheckEvent may then be used to check the signaled event and handle the data. The operation may be stopped by the DRV_FAITerminate function at any time.

x2. No Event Notification

The DRV_FAIIntStart function starts the analog input operation with interrupt transferring. The DRV_FAICheck function may be used to check the status of the operation. Meanwhile the DRV_FAITransfer function may be used to retrieve data. The operation may be stopped by the DRV_FAITerminate function when the conversion is completed or at any other time. In this type of conversion, no event notification of the acquisition status will be received. The only way to retrieve the status is to call the DRV_FAICheck to check the status of the acquisition progress.

Besides single data reading, the driver also provides the DRV_FAIIntScanStart function for multiple channel reading. For this kind of operation, you should set the buffer size (the Count parameter) to be a multiple of the number of channels. Otherwise, for cyclic mode, the first data in the buffer may not correspond to the starting channel.