/*======================================================================
| FUNCTIONS
| =====================================================================*/
static void _blast_async(int handle, int txnlen, int iter)
{
double elapsed = 0;
byte[] noresult = new byte[1];
// Make a simple queue to just assert OE.
CheetahApi.ch_spi_queue_clear(handle);
CheetahApi.ch_spi_queue_oe(handle, (byte)1);
CheetahApi.ch_spi_batch_shift(handle, 0, noresult);
// Queue the batch which is a sequence of SPI packets
// (back-to-back) each of length 4.
CheetahApi.ch_spi_queue_clear(handle);
int i;
int count = 0;
byte[] data_out = new byte[4];
for (i = 0; i < txnlen; ++i)
{
CheetahApi.ch_spi_queue_ss(handle, 0x1);
data_out[0] = (byte)((count >> 24) & 0xff);
data_out[1] = (byte)((count >> 16) & 0xff);
data_out[2] = (byte)((count >> 8) & 0xff);
data_out[3] = (byte)((count >> 0) & 0xff);
++count;
CheetahApi.ch_spi_queue_array(handle, 4, data_out);
CheetahApi.ch_spi_queue_ss(handle, 0x0);
}
ulong start = _timeMillis();
// First, submit first batch
CheetahApi.ch_spi_async_submit(handle);
int n, ret;
for (n = 0; n < iter - 1; ++n)
{
// Submit another batch, while the previous one is in
// progress. The application may even clear the current
// batch queue and queue a different set of SPI
// transactions before submitting this batch
// asynchronously.
CheetahApi.ch_spi_async_submit(handle);
// The application can now perform some other functions
// while the Cheetah is both finishing the previous batch
// and shifting the current batch as well. In order to
// keep the Cheetah's pipe full, this entire loop must
// complete AND another batch must be submitted
// before the current batch completes.
CheetahApi.ch_sleep_ms(25);
// Collect the previous batch
ret = CheetahApi.ch_spi_async_collect(handle, 0, noresult);
elapsed = ((double)(_timeMillis() - start)) / 1000;
Console.Write("collected batch #{0:d3} in {1:f2} seconds\n",
n + 1, elapsed);
if (ret < 0)
{
Console.Write("status error: {0:s}\n",
CheetahApi.ch_status_string(ret));
}
Console.Out.Flush();
start = _timeMillis();
// The current batch is now shifting out on the SPI
// interface. The application can again do some more tasks
// here but this entire loop must finish so that a new
// batch is armed before the current batch completes.
CheetahApi.ch_sleep_ms(25);
}
// Collect batch the last batch
ret = CheetahApi.ch_spi_async_collect(handle, 0, noresult);
elapsed = ((double)(_timeMillis() - start)) / 1000;
Console.Write("collected batch #{0:d3} in {1:f2} seconds\n",
n + 1, elapsed);
if (ret < 0)
{
Console.Write("status error: {0:s}\n",
CheetahApi.ch_status_string(ret));
}
Console.Out.Flush();
}