Chapter 2 - Part 1 - PPT - Mano

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Overview

• Part 1 - Registers, Microoperations and
  Implementations
• Registers and load enable
• Register transfer operations
• Microoperations - arithmetic, logic, and shift
• Microoperations on a single register
• Multiplexer-based transfers
• Shift registers
• Part 2 - Counters, Register Cells, Buses,
  Serial Operations
• Part 3 Control of Register Transfers

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Registers

• Register
• a collection of binary storage elements
• included a set of flip-flop
• n-bit register store n-bit binary information
• Frequently used to perform simple data storage
  and data movement and processing operations

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

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7-1 Register and Load Enable
Register with load enable directly through input
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7-2 Register transfer

• Large digital systems are hard to be designed by
  using state table in Chap. 5
• Large digital systems are often designed by
  modular, hierarchical approach
• Large digital systems are partitioned into two
  types of modules
• Datapath performs data-processing operations
• Control unit determine the sequence of those
  operations

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7-2 Register transfer

• The registers are assumed to be basic components
  of the digital system
• Register transfer operation movement on the data
  stored in register and the processing performed
  on the data
• Three basic components
• The set of registers in digital systems
• The operations performed on the data
• Control on the sequence of operations

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7-3 Register Transfer Operations

• Notation for register uppercase letters
  (sometime followed by numbers)
• AR address register
• PC program counter
• IP instruction register
• R2 the register 2

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7-3 Register Transfer Operations

• Data transfer from a register to another one
• R2 ?R1
• Data transfer with conditions
• If (K11) then (R2 ?R1)
• K1 R2 ?R1
• Hardware implementation

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7-3 Register Transfer Operations
More register transfer operation executed at the
same time K3 R2 ?R1, R1 ?R2
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7-4 A note for VHDL and Verilog
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7-5 Microoperation

• An elementary operations performed on data stored
  in registers or in memory.
• Transfer
• Arithmetic
• Logic perform bit manipulation on data in
  register
• Bitwise AND, Bitwise OR .
• Shift

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Arithmetic Microoperations
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Arithmetic Microoperations

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

Fig. 7.6 Implementation