OverviewPart 1 - Registers, Microoperations and ImplementationsRegisters and load enableRegister transfer operationsMicrooperations - arithmetic, logic, and shiftMicrooperations on a single registerMultiplexer-based transfersShift registersPart 2 - Counters, Register Cells, Buses, & Serial OperationsPart 3 Control of Register Transfers

RegistersRegister a collection of binary storage elements included a set of flip-flopn-bit register store n-bit binary informationFrequently used to perform simple data storage and data movement and processing operations

7-1 Register and Load Enable Register with load enable by clock gating

7-1 Register and Load EnableRegister with load enable directly through input

7-2 Register transferLarge digital systems are hard to be designed by using state table in Chap. 5Large digital systems are often designed by modular, hierarchical approachLarge digital systems are partitioned into two types of modules Datapath: performs data-processing operationsControl unit: determine the sequence of those operations

7-2 Register transferThe registers are assumed to be basic components of the digital systemRegister transfer operation: movement on the data stored in register and the processing performed on the data Three basic componentsThe set of registers in digital systemsThe operations performed on the dataControl on the sequence of operations

7-3 Register Transfer OperationsNotation for register: uppercase letters (sometime followed by numbers)AR: address registerPC: program counterIP: instruction registerR2: the register 2

7-3 Register Transfer OperationsData transfer from a register to another one R2 R1Data transfer with conditionsIf (K1=1) then (R2 R1)K1: R2 R1Hardware implementation

7-3 Register Transfer OperationsMore register transfer operation executed at the same time:K3: R2 R1, R1 R2

7-4 A note for VHDL and Verilog

7-5 MicrooperationAn elementary operations performed on data stored in registers or in memory.Transfer ArithmeticLogic: perform bit manipulation on data in registerBitwise AND, Bitwise OR .Shift

Arithmetic Microoperations

Arithmetic Microoperations

The control variable X selects the operation, and the control variable K1 loads the result in to R1. Fig. 7.6 Implementation

States: 22 = 4Input Combinations: 22 = 4Output Combinations: 22 = 4Y = AA(t+1) = INMooreStates = 2nInput Combinations = 2nOutput Combinations = 2n