在現今的SOC系統驗證上,都會加入BIST的電路,除了能加快Debug 的速度跟Error correlation 的機制來做到自我校正的功能, 不過一般最常用在Memory testing上,因為Memory 的排列排列方式具有規則性, 分成 bank, page... location, Method read/write, 可以很簡單的用 Fault table 做查表把Fault location 的位置mapping到其他的記憶體位置.也可以加入Row / Column Detection 把 Fault的 值做 update. 底下我們用最簡單的 Fault Table 來實現.
sample code
bist.cpp
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <boost/crc.hpp>
#include <sstream>
#include <string>
#define MEMDEEP 10
bool Debug = false;
#ifdef DEBUG
Debug =true;
#endif
using namespace std;
struct MEM {
unsigned int Addr;
unsigned int Val;
unsigned int CkSum;
unsigned int Crc32;
unsigned int Status;
};
struct ErrTable{
unsigned int Org_Addr;
unsigned int Nw_Addr;
};
void ProWriteMEM(struct MEM *Ptr,unsigned int Addr,unsigned int Val);
void ProReadMEM(struct MEM *Ptr,unsigned int Addr,unsigned int *Val);
void ProCheckErrTable();
unsigned ProCheckSum(unsigned int x);
//=====================================
// Num of 1's counts
//=====================================
unsigned int ProCheckSum(unsigned x) {
x = x - ((x >> 1) & 0x55555555);
x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
x = (x + (x >> 4)) & 0x0F0F0F0F;
x = x + (x >> 8);
x = x + (x >> 16);
return x & 0x0000003F;
}
//=====================================
// CRC32 Check
//=====================================
unsigned int GetCrc32(const string my_string) {
boost::crc_32_type result;
result.process_bytes(my_string.data(), my_string.length());
return result.checksum();
}
void ProWriteMEM(struct MEM *Ptr,unsigned int Addr,unsigned int Val){
Ptr->Addr = Addr;
Ptr->Val = Val;
Ptr->CkSum = ProCheckSum(Val);
string s;
stringstream out;
out << Val;
s = out.str();
Ptr->Crc32 = GetCrc32(s);
}
void ProReadMEM(struct MEM *Ptr,unsigned int Addr,unsigned int *Val){
// Ptr->Addr
*Val = Ptr->Val;
}
void ProWriteErrTable(struct ErrTable *Ptr,unsigned int Org,unsigned int Nw){
Ptr->Org_Addr = Org;
Ptr->Nw_Addr = Nw;
}
void ProReadErrTable(struct ErrTable *Ptr,unsigned int *Org,unsigned int *Nw){
*Org = Ptr->Org_Addr;
*Nw = Ptr->Nw_Addr;
}
int CheckErrTable(struct ErrTable *Ptr[],unsigned int Org,unsigned int *Nw){
int i,r;
unsigned int Org_Addr,Nw_Addr;
for(i=0; i<MEMDEEP; i++){
ProReadErrTable(Ptr[i],&Org_Addr,&Nw_Addr);
if(Debug ==true){
printf("Table ID:: %d, Org_Addr ::%x, Nw_Addr ::%x\n",i,Org_Addr,Nw_Addr);
}
if( Org == Org_Addr && Org_Addr != Nw_Addr ){
*Nw = Nw_Addr;
r= 0;
break;
}else{
r= -1;
}
}
return r;
}
int main(int argc,char *argv[]){
struct MEM *MEMPtr[MEMDEEP];
struct ErrTable *ErrPtr[MEMDEEP];
int i;
for(i=0; i<MEMDEEP; i++){
MEMPtr[i] = (struct MEM *) malloc( sizeof(struct MEM ) );
ErrPtr[i] = (struct ErrTable *) malloc( sizeof(struct ErrTable) );
}
//Initial Set 2 MEM
ProWriteMEM(MEMPtr[0],0x00000000,0);
ProWriteMEM(MEMPtr[1],0x00000004,1);
ProWriteMEM(MEMPtr[2],0x00000008,2);
ProWriteMEM(MEMPtr[3],0x0000000c,3);
ProWriteMEM(MEMPtr[4],0x00000010,4);
//Set the Fault Loc @ ErrTable
ProWriteErrTable(ErrPtr[0],0x00000008,0x00000018);
ProWriteMEM(MEMPtr[5],0x00000018,2);
ProWriteErrTable(ErrPtr[1],0x0000000c,0x00000001c);
ProWriteMEM(MEMPtr[6],0x0000001c,3);
//Check Fault Loc exists or not
unsigned int Org_Addr,Nw_Addr,rst;
Org_Addr = 0x00000008;
int c = CheckErrTable(ErrPtr,Org_Addr,&Nw_Addr);
cout <<c<<endl;
if( c != -1 ){
for(i=MEMDEEP>>1; i<MEMDEEP; i++){
if( MEMPtr[i]->Addr == Nw_Addr ){
ProReadMEM(MEMPtr[i],Nw_Addr,&rst);
printf("Find Fault @ %x -> %x :: data %d\n",Org_Addr,Nw_Addr,MEMPtr[i]->Val);
}
}
}
free(*MEMPtr);
free(*ErrPtr);
return 0;
}
compile
g++ -I/${boost_lib} -o bist bist.cpp
Refs:
CRC32 Boost c++
Check number of 1's counts
c++ int2string
code download
here
