Lecture-5
m- Bit register:
Let us see how a memory is developed and how the data can
be written into and read from it. As discussed in previous lecture,
memory is storage device and it is used to store both instructions and
data. The smallest unit of information a digital system can store is a
binary digit (Bit) which has a logic value of ‘0’ and ‘1’. A bit of data is
stored in a flip-flop. It is a general memory cell and has two states in
which it can remain indefinitely as long as power is not interrupted.
The output can be changed only if the input signals allow for it.
D flip-flop is the simplest flip-flop to store one bit of information.
The input data (bit) is stored at the active edge of the clock. To store
several bits of data simultaneously, the clock inputs of several D flip-
flops are connected in parallel to form an m-bit register (‘m’ may be 4,
6 or 8) as shown in fig.2.7. Such registers store m-bits of data D0 to
Dm-1 under the control of the clock and provide m-bits of data output
Q0 to Qm-1.
Fig.2.7 Basic Structure of m-bit Register
, The act of storing data in a register is a write operation.
Determining the value of the content of a register is a read operation.
The m-bits of data stored in a register make up a word. A word is
simply a number of contiguous bits operated upon or considered by
the hardware of microprocessor as a group. The number of bits in the
word ‘m’ is a word length. The ‘m’ inputs to the register are provided
by an m-bit input data bus and the ‘m’ outputs by an m-bit output data
bus. A bus is a number of signal lines grouped together because of
similarity of function, which connect two or more systems or
subsystem. 8-bit registers are often called octal registers.
Several equal length registers can be incorporated in a single
IC and share a common set of inputs, a common set of inputs and a
single clock such a circuit is referred to as a memory. Each register
occupies a distinct location, which has a unique numerical address.
Thus, memory can be thought of as a collection of addressable
registers. Logic is necessary to decode address inputs to ensure that
only a single register outputs its contents when data is being read
from the memory, and only a single register stores the data in it when
the data is being written into the memory.
Development of Memory Chip
Let us consider a memory of 16 words, each of 8 bits is to be
developed. 16 words can be stored in 16 memory locations, each
having a unique address and each location being capable of
containing 8 bits of data. To address 16 memory locations, 16 unique
m- Bit register:
Let us see how a memory is developed and how the data can
be written into and read from it. As discussed in previous lecture,
memory is storage device and it is used to store both instructions and
data. The smallest unit of information a digital system can store is a
binary digit (Bit) which has a logic value of ‘0’ and ‘1’. A bit of data is
stored in a flip-flop. It is a general memory cell and has two states in
which it can remain indefinitely as long as power is not interrupted.
The output can be changed only if the input signals allow for it.
D flip-flop is the simplest flip-flop to store one bit of information.
The input data (bit) is stored at the active edge of the clock. To store
several bits of data simultaneously, the clock inputs of several D flip-
flops are connected in parallel to form an m-bit register (‘m’ may be 4,
6 or 8) as shown in fig.2.7. Such registers store m-bits of data D0 to
Dm-1 under the control of the clock and provide m-bits of data output
Q0 to Qm-1.
Fig.2.7 Basic Structure of m-bit Register
, The act of storing data in a register is a write operation.
Determining the value of the content of a register is a read operation.
The m-bits of data stored in a register make up a word. A word is
simply a number of contiguous bits operated upon or considered by
the hardware of microprocessor as a group. The number of bits in the
word ‘m’ is a word length. The ‘m’ inputs to the register are provided
by an m-bit input data bus and the ‘m’ outputs by an m-bit output data
bus. A bus is a number of signal lines grouped together because of
similarity of function, which connect two or more systems or
subsystem. 8-bit registers are often called octal registers.
Several equal length registers can be incorporated in a single
IC and share a common set of inputs, a common set of inputs and a
single clock such a circuit is referred to as a memory. Each register
occupies a distinct location, which has a unique numerical address.
Thus, memory can be thought of as a collection of addressable
registers. Logic is necessary to decode address inputs to ensure that
only a single register outputs its contents when data is being read
from the memory, and only a single register stores the data in it when
the data is being written into the memory.
Development of Memory Chip
Let us consider a memory of 16 words, each of 8 bits is to be
developed. 16 words can be stored in 16 memory locations, each
having a unique address and each location being capable of
containing 8 bits of data. To address 16 memory locations, 16 unique
