#include "AliAltroDecoder.h"
#include "AliAltroData.h"
+// Class for fast decoding of RCU/Altro raw data format (DDL format)
+// to PC readable form. The decoding is done in 3 steps.
+// 1) The RCU payload consistist of a variable number of 160 bit words
+// denoted a DDL block. All the DDL blocks of an RCU payload is transformed
+// to 16 integers wich is then put into a buffer of integers big enought to contain the
+// biggest number of samples possible
+// 2) The decoded buffer is then accesible for the NextChannel functions wich reads
+// the altro channel data (samples) contained in the payload. The first call to NextChannel gives the
+// last altro channel of the back linked list, the next call the second last channel ..etc untill
+// all channles are read.
+// 3) (optional) For each Altro channel one chan invoke the member function NextBunch which gives on first call
+// The last bunch (the bunch with the highest timestamp), on next call the second last bunch..etc
+// untill all bunches are read
+
+
ClassImp(AliAltroDecoder)
AliAltroDecoder::AliAltroDecoder() : f32DtaPtr(0),
f8DtaPtr(0),
- fN32HeaderWords(8),
+ fkN32HeaderWords(8),
fN40AltroWords(0),
fN40RcuAltroWords(0),
fNDDLBlocks(0),
fIsDecoded(kFALSE),
fIsFatalCorruptedTrailer(kTRUE)
{
- // see header file for class documentation
+ // Default constructor
}
AliAltroDecoder::~AliAltroDecoder()
{
- // see header file for class documentation
+ // Default destructor
}
-Bool_t AliAltroDecoder::CheckPayloadTrailer()
+Bool_t AliAltroDecoder::CheckPayloadTrailer() const
{
- // see header file for documentation
+ //Check wether or not there is consistency between the number of 40 bit altro words given by
+ //the RCU payload and the number of 40 bit words calculated from the size of the RCU payload.
+
if(fN40AltroWords != fN40RcuAltroWords)
{
return kFALSE;
Bool_t AliAltroDecoder::Decode()
{
+ // Decodes the RCU payload (all altro channels in one go) from the DDL format to
+ // PC readable form
+
if( fIsFatalCorruptedTrailer == kTRUE)
{
printf("\n AliAltroDecoder::Decode(), WARNING, attempt to decode badly corrupted data\n");
fComplete = 0;
fInComplete = 0;
- Int_t tmpcnt = countAAApaddings();
+ Int_t tmpcnt = CountAAApaddings();
if(tmpcnt == 3)
{
Bool_t AliAltroDecoder::NextChannel(AliAltroData *altroDataPtr)
{
+ // Reads the next altro channel in the RCU payload after the RCU payload
+ // has been decoded. The channles are read strarting from the end (backlinked list)
+ // Returns kTRUE as long as ther are unread channles in the payload
+ // Returns kFALSE when all the channels has been read.
+
if(fIsFatalCorruptedTrailer == kTRUE)
{
printf("\n AliAltroDecoder::NextChannel(), WARNING, attempt to decode badly corrupted data\n");
Decode();
}
- if(fOutBufferIndex > fN32HeaderWords)
+ if(fOutBufferIndex > fkN32HeaderWords)
{
if((fOutBuffer[fOutBufferIndex] << 4 ) | ((fOutBuffer[fOutBufferIndex-1] & 0x3c0) >> 6) == 0x2aaa)
{
}
}
-
-Int_t AliAltroDecoder::countAAApaddings()
+Int_t AliAltroDecoder::CountAAApaddings() const
{
+ // Use for simulated data only.
+ // Patch for incorrectly simulated data. Counts the number of
+ // 2aaa word in the trailer of the payload and tries to figure out
+ // the correct number of 40 bit altro words in the RCU pauload
+
UShort_t *tailPtr= (UShort_t *)(f32DtaPtr +f32PayloadSize);
Int_t cnt = 0;
Float_t AliAltroDecoder::GetFailureRate()
{
- // see header file for documentation
+ // Prints to stdout the percent of altroblocks that
+ // is missing the 2aaa trailer.
+
Float_t tmp = 0;
cout << "Number of Complete channles = " << fComplete <<endl;
cout << "Number of InComplete channles = " << fInComplete <<endl;
void AliAltroDecoder::PrintInfo(AliAltroData &altrodata, Int_t n, Int_t nPerLine)
{
- // see header file for documentation
+ // prints data and address information contained in altrodata
+ // to the standard output
+
cout << "altrodata.fDataSize = " << altrodata.GetDataSize() << endl;
cout << "altrodata.fHadd = " << altrodata.GetHadd() <<endl;
const UInt_t* data = altrodata.GetData();
int AliAltroDecoder::SetMemory(UChar_t *dtaPtr, UInt_t size)
{
+ // Sets the pointer to the memory block that should be decoded
+ // Returns a negative value if an inconsistency in the data is detected
+
int iRet = 0;
Int_t tmpTrailerSize;
fIsDecoded = kFALSE;
tmpTrailerSize = 1; //assume that last word is ONE, and that the this word gives the number of 40 bit altro words
}
- f32PayloadSize = fSize/4 - (fN32HeaderWords + tmpTrailerSize);
+ f32PayloadSize = fSize/4 - (fkN32HeaderWords + tmpTrailerSize);
fN40AltroWords = (32*f32PayloadSize)/40;
fNDDLBlocks = f32PayloadSize/5;
f32LastDDLBlockSize = f32PayloadSize%DDL_32BLOCK_SIZE;
{
f32DtaPtr = f32DtaPtr - tmpTrailerSize;
fN40RcuAltroWords = *f32DtaPtr;
- f32DtaPtr = (UInt_t *)dtaPtr + fN32HeaderWords;
+ f32DtaPtr = (UInt_t *)dtaPtr + fkN32HeaderWords;
fIsFatalCorruptedTrailer = kFALSE;
}
else
fIsFatalCorruptedTrailer = kTRUE;
iRet = -1;
}
-
return iRet;
void AliAltroDecoder::DecodeDDLBlock()
{
- // see header file for documentation
+ //Decode one 160 bit DDL block into 16 x 16 bit integers (only least significant 10 bits are filled)
+
fOutBuffer[fOutBufferIndex] = *f32DtaPtr & 0x3ff; //s0
fOutBufferIndex ++;
fOutBuffer[fOutBufferIndex] = (*f32DtaPtr & 0xffc00) >> 10; //s1
void AliAltroDecoder::DecodeLastDDLBlock()
{
- // see header file for documentation
+ // Decode one 160 bit DDL block into 16 integers.
+ // In order to use the same decoding function (DecodeDDLBlock())
+ // a copy of the the last DDL block is made and
+ // if the las block does not align with 160 bits then it is padded with zeroes
+
for(Int_t i=0; i < f32LastDDLBlockSize; i++)
{
fDDLBlockDummy[i] = *f32DtaPtr;
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff