Work with the card begins from its opening. (see function XdspOpenDevice).
Before closing the supplement working with the card all the cards that were
working need to be closed. (see function XdspCloseDevice).
After opening the card you may chose the modes of its work (DAC memory signal
generation permitted, apparatus interruption work mode, Receiving pointer for
DMA buffer etc.).
Sampling process starting (input signal digitalising and output signal synthesis
if this mode is on) is executed by the function XdspSampleStart. After calling
the command XdspSampleStart the card goes to the input signal digitalising mode
and its writing to the internal memory of the ADC. If signal generation from DAC
memory is on (see functions XdspDACEnable, XdspDACDisable), then simultaneously
with input signal digitalising the card synthesises the output signal the form
of which is given by DAC memory. (Internal buffers of the synthesised and
digitalised signals have the same dimensions:
256Ê notes).
When the internal memory is full the card sets a flag in the status register and
generates apparatus interruption if it is permitted (see functions
XdspSampleInterruptEnable, XdspSampleInterruptDisable). If the mode of executing
DMA transaction is permitted then after the sampling process is finished(see
functions XdspChainSampleDMAEnable, XdspChainSampleDMADisable) the card goes to
the DMA transaction mode of internal ADC memory copying to the DMA buffer
of the PC. You can activate DMA transaction separately by calling the function
XdspDMATransactionStart.
As in the sampling process after DMA transaction is finished the card sets a
flag in the status register and generates interruption if it's permitted.
(see functions XdspDMAInterruptEnable, XdspDMAInterruptDisable).
After sampling and DMA transaction processes are finished the digitalised input
signal may be read in the "Master" mode through the pointer to DMA
buffer (see function XdspGetDMABufferPtr). Then the received digitalised signal
is processed. After this processing the sampling process, process of ADC memory
reading and processing may be repeated cyclically.
Let's see samples of working with the card:
"Master" mode signal digitalising with
interruption permitted.
Basic sample text forDelphi:
// We connect the module with descriptions of constant values,types and imported functions
Uses XdspAPI_DLL.pas;
Const
ADCBufLen=262143;// Full volume of ADC buffer, 256K of double words
Var
device0 : TDeviceHandle; // Variable for device descriptor storage
intr_hnd : THandle; // Variable for interruption waiting object descriptor storage
// DMA buffer pointer, type PDmaMemoryBuffer is distinguished as pointer to the block of
// 256Ê double words(maximum volume of the buffer sent by DMA transaction)
dma_buffer : PDmaMemoryBuffer;
signal_ch1 : Array[0..ADCBufLen] Of SmallInt; // Buffer for digitalised signal of the 1st channel
signal_ch2 : Array[0..ADCBufLen] Of SmallInt; // Buffer for digitalised signal of the 2nd channel
signals_sum : Array[0..ADCBufLen] Of SmallInt; // Buffer for the sum of 2 channels
i : Integer;
//Procedure of opening and preparing of the card for work
Procedure XDSP_Device_Open;
Begin
// Open card ¹0 and save its descriptor
device0:=XdspOpenDevice(0);
If device0=XDSP_INVALID_DEVICE_HANDLE Then ; // mistake processsing-informing the user etc.
// Receive descriptor for waiting for interruption
result:=XdspGetInterruptEventHandle(device0,@intr_hnd);
If result=XDSP_STATUS_ERROR Then ; // mistake processing - informing the user etc.
// Receive poiter to DMA buffer
result:=XdspGetDMABufferPtr(device0,@dma_buffer);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Permit automatic DMA transaction after the sampling process is finished
result:=XdspChainSampleDMAEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Permit interruption generation after DMA transaction process is finished
result:=XdspDMAInterruptEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Give dimensions of DMA transaction
result:=XdspSetDMABufferLength(hndDrv,(ADCBufLen+1));
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
End;
//Card closing process
Procedure XDSP_Device_Close;
Begin
// Close card with descriptor device0
result:=XdspCloseDevice(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
End;
//Signal digitalising, ADC memory reading and channels sepatating procedure
Procedure XDSP_Device_Sample;
Begin
// Start signal digitalising process with automatic DMA transaction
result:=XdspResetAll;
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
result:=XdspSampleStart;
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Waiting for the end of digitalising process + DMA transaction (waiting for event on interruption, time-out 100 ms.)
If WaitForSingleObject(intr_hnd,100)=WAIT_OBJECT_0 Then Begin
// Interruption executed, we can work with the ADC memory presenting in the DMA buffer
// adc_mem data separating to two channels signal_ch1, signal_ch2
For i:=0 To ADCBufLen Do Begin
dwData:=dma_buffer^[i+1]; // DMA buffer block begins with index 1
signal_ch1[i]:=dwData;
dwData:=dwData shr 16;
signal_ch2[i]:=dwData;
End;
End Else Begin
// Interruption received, mistake processing ...
End;
End;
//Initialising the card, digitalising the signal and its processing
Begin
XDSP_Device_Open; // Open and initialise the card
// Cyclic process of digitalising the signal and its processing
Repeat
XDSP_Device_Sample; // Data digitalising,copying to adc_mem and separating to channels
// Digitalised signals processing sample - summed signal of two channels calculating
For i:=0 To ADCBufLen Do singals_sum[i]:=signal_ch1[i]+signal_ch2[i];
// For example presenting or storaging the signals ...
Until [exit conditions];
XDSP_Device_Close; // Closing the card
End;
Forming
synthesised signal presenting in the DAC memory
("Target" mode).
Èñõîäíûé òåêñò ïðèìåðà äëÿ Delphi:
// Connect module with descriptions of constant values and of types of imported functions
Uses XdspAPI_DLL.pas;
Const
ADCBufLen=262143;// ADC buffer full volume, 256Ê bouble words
Var
device0 : TDeviceHandle; // Variable for storage of the descriptor of the device
intr_hnd : THandle; // Variable for storage of the descriptor of the objectof waiting for interruption
// Pointer to DMA buffer, type PDmaMemoryBuffer is distinguished as pointer to the block of 256Ê double words ( maximum volume of the buffer transmitted by DMA transaction)
dma_buffer : PDmaMemoryBuffer;
dac_signal : Array[0..ADCBufLen] Of SmallInt; // Buffer for the storage of the synthesised signal presenting
signal_ch1 : Array[0..ADCBufLen] Of SmallInt; // Buffer for digitalised signal of the 1st channel
signal_ch2 : Array[0..ADCBufLen] Of SmallInt; // Buffer for digitalised signal of the 2nd channel
i : Integer;
//Procedure of opening and preparing card for work
Procedure XDSP_Device_Open;
Begin
// Open card ¹0 and save its descriptor
device0:=XdspOpenDevice(0);
If device0=XDSP_INVALID_DEVICE_HANDLE Then ; // mistake processsing-informing the user etc.
// Get the descriptor for waiting for interruptuion
result:=XdspGetInterruptEventHandle(device0,@intr_hnd);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Get the pointer to DMA buffer
result:=XdspGetDMABufferPtr(device0,@dma_buffer);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Permit automatic DMA transaction when the sampling process is finished
result:=XdspChainSampleDMAEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Permit interruption generation when the DMA transaction process is finished
result:=XdspDMAInterruptEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Give the dimensions of DMA transaction
result:=XdspSetDMABufferLength(hndDrv,(ADCBufLen+1));
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
End;
Procedure XDSP_Device_Close;
Begin
// Close card with device0 descriptor
result:=XdspCloseDevice(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
End;
//Procedure of writing the synthesised signal presenting to the DAC memory
Procedure XDSP_Write_DAC_Memory;
Begin
result:=XdspResetAll;
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// DAC memory access in "Target" mode permitted
result:=XdspTargetModeEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// writing data from dac_signal block to the DAC memory
For i:=0 to ADCBufLen Do Begin
dwResult:=XdspWriteDACMemDWORD(device0,i,dac_signal[i]);
End;
// DAC memory access in "Target" mode banned
result:=XdspTargetModeDisable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
End;
//Signal digitalising,ADC memory reading and channel separating process
Procedure XDSP_Device_Sample;
Begin
//Start the signal digitalising process with automatic DMA transaction
result:=XdspResetAll;
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
result:=XdspSampleStart;
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Waiting for the end of the digitalising process + DMA transaction(waiting for event on interruption, time-out 100 msñ.)
If WaitForSingleObject(intr_hnd,100)=WAIT_OBJECT_0 Then Begin
// Interruption received, can work with ADC memory presenting in the DMA buffer
// adc_mem data separating to two channels signal_ch1, signal_ch2
For i:=0 To ADCBufLen Do Begin
dwData:=dma_buffer^[i+1]; // DMA buffer block begins with index 1
signal_ch1[i]:=dwData;
dwData:=dwData shr 16;
signal_ch2[i]:=dwData;
End;
End Else Begin
// Interruption not received, mistake processing ...
End;
End;
//Initialising the card,DAC output permission, signal digitalising and processing
Begin
XDSP_Device_Open; // Open and initialise the card
// forming of the synthesised signal presenting in the block dac_signal
For i:=0 To ADCBufLen Do Begin
dac_signal[i]:=512+256+Trunc(255*sin(i*Pi/180)); // sinus with 0 level 256 and 255 range
End;
// Synthesised signal presenting storage to the DAC memory
XDSP_Write_DAC_Memory;
// Signal synthesis permission
result:=XdspDACEnable(device0);
If result=XDSP_STATUS_ERROR Then ; // mistake processsing-informing the user etc.
// Cyclic process of sampling and processing of the digitalised signal
Repeat
XDSP_Device_Sample; // Data digitalising, copying to adc_mem and separating to channels
// For example processing presenting or storage of the signals...
Until [exit condition];
XDSP_Device_Close; // close the card
End;
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