bool ISpiDriver.Xaction_nWrite16_nRead16(ref SpiXaction Transaction)
{
if (Transaction.WriteCount <= 0)
{
Debug.Assert(false, "Transaction.WriteCount is 0.");
Trace.WriteLine("Error: The write buffer in a SPI transaction cannot be empty.");
return(false);
}
if (Transaction.WritePtr == IntPtr.Zero)
{
Debug.Assert(false, "Transaction.write buffer is null.");
Trace.WriteLine("Error: The write buffer in a SPI transaction cannot be null.");
return(false);
}
if ((Transaction.ReadCount > 0) && (Transaction.ReadPtr == IntPtr.Zero))
{
Debug.Assert(false, "Transaction.read buffer is null.");
Trace.WriteLine("Error: The read buffer in a SPI transaction cannot be null.");
return(false);
}
ushort[] writeData;
int length = Transaction.ReadCount + Transaction.ReadStartOffset;
if (length < Transaction.WriteCount)
{
length = Transaction.WriteCount;
}
writeData = new ushort[length];
// marshal the pointer to an array
for (int i = 0; i < Transaction.WriteCount; i++)
{
writeData[i] = (ushort)Marshal.ReadInt16(Transaction.WritePtr, i * 2);
}
// repeat the last byte if neccessary to fill up writeData
for (int i = Transaction.WriteCount; i < writeData.Length; i++)
{
writeData[i] = writeData[Transaction.WriteCount - 1];
}
ushort[] readData = _spiDeviceCurrent.DeviceWrite(writeData);
if (Transaction.ReadPtr != IntPtr.Zero)
{
Utility.MarshalUshort(Transaction.ReadPtr, Transaction.ReadCount, Transaction.ReadStartOffset, readData);
}
return(true);
}
bool ISpiDriver.Xaction_nWrite16_nRead16(ref SpiXaction Transaction)
{
if (Transaction.WriteCount <= 0)
{
Debug.Assert(false, "Transaction.WriteCount is 0.");
Trace.WriteLine("Error: The write buffer in a SPI transaction cannot be empty.");
return(false);
}
ushort[] writeData;
if (Transaction.ReadPtr == IntPtr.Zero)
{
writeData = new ushort[Transaction.WriteCount];
}
else
{
if (Transaction.ReadStartOffset > Transaction.WriteCount || Transaction.ReadStartOffset < 0)
{
Debug.Assert(false, "ReadStartOffset is invalid");
Trace.WriteLine("Error: ReadStartOffset of the SPI transaction is invalid.");
return(false);
}
writeData = new ushort[Transaction.ReadCount + Transaction.ReadStartOffset];
if (writeData.Length < Transaction.WriteCount)
{
Debug.Assert(false, "The read count (including offset) needs to be no less than the write count.");
Trace.WriteLine("Error: Read count (including offset) should be no less than the write count in a SPI transaction.");
return(false);
}
}
// marshal the pointer to an array
for (int i = 0; i < Transaction.WriteCount; i++)
{
writeData[i] = (ushort)Marshal.ReadInt16(Transaction.WritePtr, i * 2);
}
// repeat the last byte if neccessary to fill up writeData
for (int i = Transaction.WriteCount; i < writeData.Length; i++)
{
writeData[i] = writeData[Transaction.WriteCount - 1];
}
ushort[] readData = _spiDeviceCurrent.DeviceWrite(writeData);
if (readData.Length != writeData.Length)
{
Debug.Assert(false, "read data length expected to be write data length");
Trace.WriteLine("Error: Read data and write data should have the same length in a SPI transaction.");
return(false);
}
if (Transaction.ReadPtr != IntPtr.Zero)
{
Utility.MarshalUshort(Transaction.ReadPtr, Transaction.ReadCount, Transaction.ReadStartOffset, readData);
}
return(true);
}