For http://www.psi.ch/drs/DocumentationEN/manual_rev20.pdf:

0 0x02 15..8 board_type 5 for DRS4 USB Evaluation Board 1.1 ---> should instead say Evaluation Board 2.0 ?

 I've been reviewing DRS.cpp v4.0.1

1) if(i==100) should be if(i==1000) in function int DRSBoard::SetFrequency(double demand, bool wait)

Otherwise if PLL did not lock, i = 1000, and the if statement is evaluating it against 100, not 1000 so it never gets triggered and the error goes unnoticed.

      if (wait) {

         StartDomino();

         for (i=0 ; i<1000 ; i++)

         if (GetStatusReg() & BIT_PLL_LOCKED0)

            break;

         SoftTrigger();

         if (i==100) {

            printf("PLL did not lock for frequency %lf\n", demand);

            return 0;

         }

      }

2) int DRSBoard::RegulateFrequency(double demand) does not seem to work at all, the frequency does not lock for either 2 or 5 GHz, tested using DRS4 v2.0 eval board with DRS v4.0.1 and v2.0.1 software's drscl tool.

3) In int DRSBoard::SetTriggerDelayPercent(int delay) and int DRSBoard::SetTriggerDelayNs(int delay), what is the purpose of Read and setting of "reg" if it's not being used or exported anywhere else outside of that function? Seems like Read and reg are called for nothing.

      Read(T_CTRL, &reg, REG_TRG_DELAY, 2);

      reg = (reg & 0xFF00) | ticks;

      Write(T_CTRL, REG_TRG_DELAY, &ticks, 2);

Also, I don't understand why in int DRSBoard::SetSyncDelay(int ticks), the code changes to 
      Read(T_CTRL, &reg, REG_TRG_DELAY, 2);
      reg = (reg & 0xFF) | (ticks << 8);
      Write(T_CTRL, REG_TRG_DELAY, &reg, 2);
In particular, reg = (reg & 0xFF00) | ticks; and reg = (reg & 0xFF) | (ticks << 8);  I'm not really sure but doesn't Read() with size 2 return a value that has a maximum value of 0xFF, or 8bits? But ticks << 8, since ticks == 255 max, makes 255 << 8 => 65280, which is now a 16bit value and size 4. No? I might be wrong here, and if I am then I don't understand what's going on. Can you please explain? In v2.0.1 the ticks were a maximum of 511 or 9bits, why did it change to 8bits?

4) A function is being called incorrectly in GetWave() in DRS.cpp

int DRSBoard::GetWave(unsigned int chipIndex, unsigned char channel, float *waveform)
{
   return GetWave(chipIndex, channel, waveform, true, fStopCell[chipIndex], false, 0, true);
}

The return is calling the following overloaded function:
int DRSBoard::GetWave(unsigned int chipIndex, unsigned char channel, float *waveform, bool responseCalib, int triggerCell, int wsr, bool adjustToClock, float threshold, bool offsetCalib)
the problem is that int wsr is not passed to the function and it thus causes implicit conversions where false is being cast into int, 0 into bool, and true into float.

I'll post more if I have any questions or spot any more bugs.