TAC Three address code Three-address code (TAC) will be the intermediate representation used in our Decaf compiler. It is essentially a generic assembly language that falls in the lower-end of the mid-level IRs. Many compilers use an IR similar to TAC. It is a sequence of instructions, each of which can have at most three operands. The operands could be
TAC Handout written by Maggie Johnson and revised by me. Three address code Three-address code(TAC) will be the intermediate representation used in our Decaf compiler. It is essentially a generic assembly language that falls in the lower-end of the mid-level IRs. Some variant of 2, 3 or 4 address code is fairly commonly used as an IR, since it maps well to most
Sequential Circuit Models Yo Combinational logic Universal combinational circuit model No memory units No feedback from logic outputs back to the inputs
Hazard o Boolean algebra does not account for propagation delays through signal paths of actually circuits. o The delay can cause glitches to occur. A glitch is an unwanted signal, usually short pulse caused by the transient behavior of signal path that have different delays A hazard exists any time the potential for glitches is present
Digital system: entity can process, transfer and store any kind of digital signals is Composed of individual digital logic circuits which are designed to perform specified function
Positional Number System Number system use positional notation to represent value. The position of the character(numeral) in a character string (collection of possible numerals) indicate value as well as the character itself. Radix (base) is the number of numeral characters in the character set of positional number system. Position Weiaht is a constant that represents the value of a position. Different position has different weight. It is the integer power of radix