Synopsys:
pokel NENC,ENDIAN,BITS
Given an IOS descriptor, a bit-offset and a long value of BITS bits, poke it. Use the negative encoding and endianness specified in the instruction arguments.
In case of an error, this instruction pushes an exception describing the error condition. Otherwise it pushes PVM_NULL.
Stack: ( INT ULONG LONG -- EXCEPTION|null )