Core TGC_X {
	architectural_state {
        unsigned int XLEN=32, FLEN=32;
        unsigned CSR_SIZE = 4096;
        unsigned REG_FILE_SIZE=32;
        unsigned fencei=1;
    	register unsigned PC [[is_pc]];
        register unsigned X[REG_FILE_SIZE];
        extern char MEM[1<<XLEN];
        extern unsigned CSR[CSR_SIZE];
        extern unsigned<XLEN> FENCE;
    }
    instructions { 
        ADDI [[hls]] {
            encoding: imm[11:0] :: rs1[4:0] :: 0b000 :: rd[4:0] :: 0b0010011;
            behavior: {
            	X[rd] = X[rs1] + imm;            
            }
        }
        SLTI {
            encoding: imm[11:0] :: rs1[4:0] :: 0b010 :: rd[4:0] :: 0b0010011;
            behavior: {
	            X[rd] = X[rs1] < imm? 1 : 0;	            
            }
        }
        SW {
            encoding: imm[11:5] :: rs2[4:0] :: rs1[4:0] :: 0b010 :: imm[4:0] :: 0b0100011;
            behavior: {
	            int offset =  X[rs1] + imm;
	            MEM[offset] = X[rs2];
            }
        }
        LW {
            encoding: imm[11:0] :: rs1[4:0] :: 0b010 :: rd[4:0] :: 0b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            behavior: if(rd!=0) X[rd]=(int)MEM[X[rs1] + imm]; 
        }
        LB {
            encoding: imm[11:0] :: rs1[4:0] :: 0b000 :: rd[4:0] :: 0b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            behavior: if(rd!=0) X[rd]=MEM[X[rs1] + imm];
        }
        LBU {
            encoding: imm[11:0] :: rs1[4:0] :: 0b100 :: rd[4:0] :: 0b0000011;
            args_disass:"{name(rd)}, {imm}({name(rs1)})";
            behavior: if(rd!=0) X[rd]=(unsigned char)MEM[X[rs1] + imm];
        }
        JAL[[no_cont]] {
            encoding:imm[20:20] :: imm[10:1] :: imm[11:11] :: imm[19:12] :: rd[4:0] :: 0b1101111;
            behavior: {
                if(rd!=0) X[rd] = (unsigned)PC;
                PC = PC+imm;
            }
        }
        CSRRCI {
            encoding: csr[11:0] :: zimm[4:0] :: 0b111 :: rd[4:0] :: 0b1110011;
            args_disass:"{name(rd)}, {csr}, {zimm:#0x}";
            behavior: {
	            unsigned<XLEN> res = CSR[csr];
	            if(rd!=0) X[rd] = res;
	            if(zimm!=0) CSR[csr] = res & ~((unsigned<XLEN>)zimm);    
            }
        }
        FENCE_I[[flush]] {
            encoding: imm[11:0] :: rs1[4:0] :: 0b001 :: rd[4:0] :: 0b0001111 ;
            behavior: FENCE[fencei] = imm;
        }
    }
}