More on debug flag
Goal: Would like to print register contents after a particular instruction is retired for debugging reasons.
Each packet type (epacket, rpacket, etc) defined in abmtypes.vhd has a boolean field called pflag. This flag is initially set by the fetch block after parsing the line for that instruction. This flag should be passed unchanged by each entity. When the instruction is RETIRED, if pflag is TRUE, then the ddr entity should set the shared variable printreg to TRUE. This will cause the registers to be printed and the printreg variable to be reset back to FALSE.
The shared variable printreg is defined in abmtypes.vhd; the code for printing the registers is already contained in the drr.vhd entity.