2. CONTENTS
• Register Transfer Language
• Register Transfer
• Bus And Memory Transfers
• Types of Micro-operations
• Arithmetic Micro-operations
• Logic Micro-operations
• Shift Micro-operations
• Arithmetic Logic Shift Unit
3. Registers
• Registers are a type of computer memory used to
quickly accept, store, and transfer data and
instructions that are being used immediately by the
CPU.
• The registers used by the CPU are often termed as
Processor registers.
4. Registers
• The next fastest thing after registers is cache
memory, which is still slower than registers.
• A register consists of a group of flip-flops and gates.
The flip-flops hold the binary information and gates
control when and how new information is
transferred into a register.
5. • A Register is a collection of flip flops.
• A flip flop is used to store single bit digital data.
• For storing a large number of bits, the storage capacity
is increased by grouping more than one flip flops.
• If we want to store an n-bit word, we have to use an n-
bit register containing n number of flip flops.
• A flip-flop is a digital memory circuit that stores one
bit of data. They are the primary blocks of the most
sequential circuits. Flip-flops act as memory elements
in a sequential circuit.
6. • A digital system is an interconnection of digital hardware modules.
• The modules are registers, decoders, arithmetic elements, and control
logic.
• The various modules are interconnected with common data and
control paths to form a digital computer system.
• Digital modules are best defined by the registers they contain and the
operations that are performed on the data stored in them.
• The operations executed on data stored in registers are called
microoperations.
• A microoperation is an elementary operation performed on the
information stored in one or more registers.
• The result of the operation may replace the previous binary
information of a register or may be transferred to another register.
• Examples of microoperations are shift, count, clear, and load.
7. REGISTER TRANSFER
LANGUAGE
• The symbolic notation used to describe the micro-
operation transfer among registers is called RTL
(Register Transfer Language).
• The use of symbols instead of a narrative
explanation provides an organized and concise
manner for listing the micro-operation sequences in
registers and the control functions that initiate them.
8. Registers
Computer registers are designated by upper case letters (and optionally
followed by digits or letters) to denote the function of the register.
13. Memory transfer
• Consider a memory unit that receives the address from a register, called the
address register, symbolized by AR.
• The data are transferred to another register, called the data register, symbolized
by DR.
• The read operation can be stated as follows: Read: DR<- M [AR]
• This causes a transfer of information into DR from the memory word M
selected by the address in AR.
• The write operation transfers the content of a data register to a memory word
M selected by the
• address. Assume that the input data are in register R1 and the address is in AR.
• The write operation can be stated as follows: Write: M [AR] <- R1
14. Types of Micro-operations
• Register Transfer Micro-operations: Transfer binary
information from one register to another.
• Arithmetic Micro-operations: Perform arithmetic
operation on numeric data stored in registers.
• Logical Micro-operations: Perform bit manipulation
operations on data stored in registers.
• Shift Micro-operations: Perform shift operations on
data stored in registers.
![Memory transfer
• Consider a memory unit that receives the address from a register, called the
address register, symbolized by AR.
• The data are transferred to another register, called the data register, symbolized
by DR.
• The read operation can be stated as follows: Read: DR<- M [AR]
• This causes a transfer of information into DR from the memory word M
selected by the address in AR.
• The write operation transfers the content of a data register to a memory word
M selected by the
• address. Assume that the input data are in register R1 and the address is in AR.
• The write operation can be stated as follows: Write: M [AR] <- R1](https://image.slidesharecdn.com/rtlintro-250403173257-ec7b1fa4/85/RTL-RTL-RTL-RTL-RTL-RTL-RTL-RTL-intro-pptx-13-320.jpg)
