For one channel now sampling rates up to 30MHz are possible.

However, buffer overflows in the usb system limit the number
of consecutive samples to 256. At 5MHz 796 samples are possible
and at 3MHz continous sampling is possible.

diff --git a/comedi/drivers/usbduxfast.c b/comedi/drivers/usbduxfast.c
index 3270233cb5a02b0c4152beb4d872208516ce0a2d..dc88bcb8662745b5a06e6da19a4f6adb1442e55a 100644 (file)
--- a/comedi/drivers/usbduxfast.c
+++ b/comedi/drivers/usbduxfast.c
@@ -1,4 +1,4 @@
-#define DRIVER_VERSION "v0.93"
+#define DRIVER_VERSION "v0.94"
 #define DRIVER_AUTHOR "Bernd Porr, BerndPorr@f2s.com"
 #define DRIVER_DESC "USB-DUXfast, BerndPorr@f2s.com"
 /*
@@ -25,7 +25,7 @@ Driver: usbduxfast.c
 Description: ITL USB-DUXfast
 Devices: [ITL] USB-DUX (usbduxfast.o)
 Author: Bernd Porr <BerndPorr@f2s.com>
-Updated: 17 Apr 2005
+Updated: 12 Jun 2005
 Status: testing
 */
 
@@ -115,7 +115,7 @@ Status: testing
 // Analogue in subdevice
 #define SUBDEV_AD             0
 
-// minimal time in nanoseconds between two samples
+// min delay steps
 #define MIN_SAMPLING_PERIOD 9 // steps at 30MHz in the FX2
 
 // Max number of 1/30MHz delay steps:
@@ -656,6 +656,7 @@ static int usbduxfast_ai_cmdtest(comedi_device *dev,
 {
        int err=0, stop_mask=0;
        long int steps,tmp=0;
+       int minSamplPer;
        usbduxfastsub_t* this_usbduxfastsub=dev->private;
        if (!(this_usbduxfastsub->probed)) {
                return -ENODEV;
@@ -730,11 +731,17 @@ static int usbduxfast_ai_cmdtest(comedi_device *dev,
                err++;
        }
 
+       if (cmd->chanlist_len==1) {
+               minSamplPer=1;
+       } else {
+               minSamplPer=MIN_SAMPLING_PERIOD;
+       }
+
        if(cmd->convert_src == TRIG_TIMER)
        {
                steps=cmd->convert_arg*30;
-               if (steps<(MIN_SAMPLING_PERIOD*1000)) {
-                       steps=MIN_SAMPLING_PERIOD*1000;
+               if (steps<(minSamplPer*1000)) {
+                       steps=minSamplPer*1000;
                }
                if (steps>(MAX_SAMPLING_PERIOD*1000)) {
                        steps=MAX_SAMPLING_PERIOD*1000;
@@ -906,7 +913,7 @@ static int usbduxfast_ai_cmd(comedi_device *dev, comedi_subdevice *s)
        if(cmd->convert_src == TRIG_TIMER) {
                steps=(cmd->convert_arg*30)/1000;
        }
-       if (steps<MIN_SAMPLING_PERIOD) {
+       if ((steps<MIN_SAMPLING_PERIOD)&&(cmd->chanlist_len!=1)) {
                printk("comedi%d: usbduxfast: ai_cmd: steps=%ld, scan_begin_arg=%d. Not properly tested by cmdtest?\n", 
                       dev->minor, 
                       steps,
@@ -934,45 +941,66 @@ static int usbduxfast_ai_cmd(comedi_device *dev, comedi_subdevice *s)
        case 1:
                if (CR_RANGE(cmd->chanlist[0])>0) rngmask=0xff-0x04; else rngmask=0xff;
                // commit data to the FIFO
-               this_usbduxfastsub->dux_commands[LENBASE+0]=1;
-               this_usbduxfastsub->dux_commands[OPBASE+0]=0x02; // data
-               this_usbduxfastsub->dux_commands[OUTBASE+0]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+0]=0;
-
-               // we have 6 states with duration 1
-               steps=steps-6;
-
-               // do the first part of the delay
-               this_usbduxfastsub->dux_commands[LENBASE+1]=steps/2;
-               this_usbduxfastsub->dux_commands[OPBASE+1]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+1]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+1]=0;
-
-               // and the second part
-               this_usbduxfastsub->dux_commands[LENBASE+2]=steps-steps/2;
-               this_usbduxfastsub->dux_commands[OPBASE+2]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+2]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+2]=0;
-               
-               this_usbduxfastsub->dux_commands[LENBASE+3]=1;
-               this_usbduxfastsub->dux_commands[OPBASE+3]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+3]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+3]=0;
-               
-               this_usbduxfastsub->dux_commands[LENBASE+4]=1;
-               this_usbduxfastsub->dux_commands[OPBASE+4]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+4]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+4]=0;
-               
-               this_usbduxfastsub->dux_commands[LENBASE+5]=1;
-               this_usbduxfastsub->dux_commands[OPBASE+5]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+5]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+5]=0;
 
-               this_usbduxfastsub->dux_commands[LENBASE+6]=1;
-               this_usbduxfastsub->dux_commands[OPBASE+6]=0;
-               this_usbduxfastsub->dux_commands[OUTBASE+6]=0xFF & rngmask;
-               this_usbduxfastsub->dux_commands[LOGBASE+6]=0;
+               if (steps<MIN_SAMPLING_PERIOD) {
+                       if (steps<=1) {
+                               // we just stay here
+                               this_usbduxfastsub->dux_commands[LENBASE+0]=0x80; // branch back to state 0
+                               this_usbduxfastsub->dux_commands[OPBASE+0]=0x03; // deceision state with data
+                               this_usbduxfastsub->dux_commands[OUTBASE+0]=0xFF & rngmask;
+                               this_usbduxfastsub->dux_commands[LOGBASE+0]=0xFF; // doesn't matter
+                       } else {
+                               this_usbduxfastsub->dux_commands[LENBASE+0]=steps-1;
+                               this_usbduxfastsub->dux_commands[OPBASE+0]=0x02; // data
+                               this_usbduxfastsub->dux_commands[OUTBASE+0]=0xFF & rngmask;
+                               this_usbduxfastsub->dux_commands[LOGBASE+0]=0;
+                       }                       
+                       this_usbduxfastsub->dux_commands[LENBASE+1]=0x00; // branch back to state 0
+                       this_usbduxfastsub->dux_commands[OPBASE+1]=0x01; // deceision state w/o data
+                       this_usbduxfastsub->dux_commands[OUTBASE+1]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+1]=0xFF; // doesn't matter
+               } else {
+                       // for slower sampling rate we loop through the idle state
+                       this_usbduxfastsub->dux_commands[LENBASE+0]=1;
+                       this_usbduxfastsub->dux_commands[OPBASE+0]=0x02; // data
+                       this_usbduxfastsub->dux_commands[OUTBASE+0]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+0]=0;
+                       
+                       // we have 6 states with duration 1
+                       steps=steps-6;
+                       
+                       // do the first part of the delay
+                       this_usbduxfastsub->dux_commands[LENBASE+1]=steps/2;
+                       this_usbduxfastsub->dux_commands[OPBASE+1]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+1]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+1]=0;
+                       
+                       // and the second part
+                       this_usbduxfastsub->dux_commands[LENBASE+2]=steps-steps/2;
+                       this_usbduxfastsub->dux_commands[OPBASE+2]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+2]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+2]=0;
+                       
+                       this_usbduxfastsub->dux_commands[LENBASE+3]=1;
+                       this_usbduxfastsub->dux_commands[OPBASE+3]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+3]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+3]=0;
+                       
+                       this_usbduxfastsub->dux_commands[LENBASE+4]=1;
+                       this_usbduxfastsub->dux_commands[OPBASE+4]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+4]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+4]=0;
+                       
+                       this_usbduxfastsub->dux_commands[LENBASE+5]=1;
+                       this_usbduxfastsub->dux_commands[OPBASE+5]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+5]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+5]=0;
+                       
+                       this_usbduxfastsub->dux_commands[LENBASE+6]=1;
+                       this_usbduxfastsub->dux_commands[OPBASE+6]=0;
+                       this_usbduxfastsub->dux_commands[OUTBASE+6]=0xFF & rngmask;
+                       this_usbduxfastsub->dux_commands[LOGBASE+6]=0;
+               }
                break;
 
        case 2: