CHAPTER SIX REGISTERS AND COUNTERS A clocked sequential circuit consists of a group of flip-flops and combinational gates connected to form a feedback.
Download ReportTranscript CHAPTER SIX REGISTERS AND COUNTERS A clocked sequential circuit consists of a group of flip-flops and combinational gates connected to form a feedback.
Slide 1
CHAPTER SIX
REGISTERS AND COUNTERS
1
Slide 2
A clocked sequential circuit consists of a group of
flip-flops and combinational gates connected to
form a feedback path.
A circuit with flip-flops is considered a sequential
circuit even in the absence of combinational
gates.
Circuits that include flip-flops are classified by
the function they perform.
Two such circuits are registers and counters.
2
Slide 3
A register is a group of flip-flops, each one of
which is capable of storing one bit of information.
An n-bit register consists of a group of n flip-flops.
A register consists of a group of flip-flops together
with gates that affect their operation. (they
determine how the information is transferred into
register).
A counter is a special type of register that goes
through a predetermined sequence of binary
states.
3
Slide 4
Four-bit register
4
Slide 5
CLEAR or RESET. When CLEAR is 0 the flip flop
is resetting independent of clock and D values. It is
useful because in digital systems when the power is
turned on the state of flip-flops is unknown. Direct
input CLEAR can bring all flip-flops to the known
starting state prior to the clock operation.
REGISTER WITH PARALLEL LOAD
The transfer of new information into a register is
referred to as loading or updating the register.
If all the bits of the register are loaded
simultaneously with a common clock pulse, we say
that the loading is done in parallel.
5
Slide 6
Two channel
mux
6
Four-bit register with parallel load
Slide 7
SHIFT REGISTERS
A register capable of shifting the binary
information held in each cell to its neighboring cell
in a selected direction is called a shift register.
It consists of a chain of flip-flops in cascade, with
the output of one flip-flop connected to the input of
the next flip-flop.
All flip-flops receive common clock pulses, which
activate the shift of data from one stage to the
next.
7
Slide 8
Four-bit shift register
input
1011
F.F #1 (0)
F.F #2 (0)
F.F #3 (0)
F.F #4 (0)
1
0
0
0
1
1
0
0
0
1
1
0
1
0
1
1
8
Slide 9
SERIAL TRANSFER
A digital system is said to operate in serial mode
when information is transferred and manipulated
one bit at a time.
Information is transferred one bit at a time by
shifting the bits out of the source register into the
destination register.
The serial transfer of information from register A
to register B is done with shift registers where
the SO of register A is connected to the SI of
register B.
We can control the shift operation by connecting
shift control with the clock through an AND gate
9
Slide 10
Serial transfer from register A to register B
10
Slide 11
11
Slide 12
In
the parallel mode, information is available from
all bits of a register and all bits can be transferred
simultaneously during one clock pulse.
In
the serial mode, the registers have a single serial
input and a single serial output. The information is
transferred one bit at a time while the registers are
shifted in the same direction.
12
Slide 13
UNIVERSAL SHIFT REGISTER
A register capable of shifting in one direction only
is a unidirectional shift register.
A register capable of shifting in both direction is a
bidirectional shift register.
If the register has both shifts and parallel-load
capabilities, it is referred to as a universal shift
register.
13
Slide 14
The most general shift register has the following
capabilities:
A clear control to clear the register to 0.
A
clock input to synchronize the operation.
A
shift-right control and the serial input & output
lines associated with it.
A
shift-left control and the serial input & output
lines associated with it.
A
parallel-load control and the n input lines
associated with the parallel transfer.
n
parallel output lines.
A
control state that leaves the information in the
register unchanged in response to the clock.
14
Slide 15
15
Slide 16
16
CHAPTER SIX
REGISTERS AND COUNTERS
1
Slide 2
A clocked sequential circuit consists of a group of
flip-flops and combinational gates connected to
form a feedback path.
A circuit with flip-flops is considered a sequential
circuit even in the absence of combinational
gates.
Circuits that include flip-flops are classified by
the function they perform.
Two such circuits are registers and counters.
2
Slide 3
A register is a group of flip-flops, each one of
which is capable of storing one bit of information.
An n-bit register consists of a group of n flip-flops.
A register consists of a group of flip-flops together
with gates that affect their operation. (they
determine how the information is transferred into
register).
A counter is a special type of register that goes
through a predetermined sequence of binary
states.
3
Slide 4
Four-bit register
4
Slide 5
CLEAR or RESET. When CLEAR is 0 the flip flop
is resetting independent of clock and D values. It is
useful because in digital systems when the power is
turned on the state of flip-flops is unknown. Direct
input CLEAR can bring all flip-flops to the known
starting state prior to the clock operation.
REGISTER WITH PARALLEL LOAD
The transfer of new information into a register is
referred to as loading or updating the register.
If all the bits of the register are loaded
simultaneously with a common clock pulse, we say
that the loading is done in parallel.
5
Slide 6
Two channel
mux
6
Four-bit register with parallel load
Slide 7
SHIFT REGISTERS
A register capable of shifting the binary
information held in each cell to its neighboring cell
in a selected direction is called a shift register.
It consists of a chain of flip-flops in cascade, with
the output of one flip-flop connected to the input of
the next flip-flop.
All flip-flops receive common clock pulses, which
activate the shift of data from one stage to the
next.
7
Slide 8
Four-bit shift register
input
1011
F.F #1 (0)
F.F #2 (0)
F.F #3 (0)
F.F #4 (0)
1
0
0
0
1
1
0
0
0
1
1
0
1
0
1
1
8
Slide 9
SERIAL TRANSFER
A digital system is said to operate in serial mode
when information is transferred and manipulated
one bit at a time.
Information is transferred one bit at a time by
shifting the bits out of the source register into the
destination register.
The serial transfer of information from register A
to register B is done with shift registers where
the SO of register A is connected to the SI of
register B.
We can control the shift operation by connecting
shift control with the clock through an AND gate
9
Slide 10
Serial transfer from register A to register B
10
Slide 11
11
Slide 12
In
the parallel mode, information is available from
all bits of a register and all bits can be transferred
simultaneously during one clock pulse.
In
the serial mode, the registers have a single serial
input and a single serial output. The information is
transferred one bit at a time while the registers are
shifted in the same direction.
12
Slide 13
UNIVERSAL SHIFT REGISTER
A register capable of shifting in one direction only
is a unidirectional shift register.
A register capable of shifting in both direction is a
bidirectional shift register.
If the register has both shifts and parallel-load
capabilities, it is referred to as a universal shift
register.
13
Slide 14
The most general shift register has the following
capabilities:
A clear control to clear the register to 0.
A
clock input to synchronize the operation.
A
shift-right control and the serial input & output
lines associated with it.
A
shift-left control and the serial input & output
lines associated with it.
A
parallel-load control and the n input lines
associated with the parallel transfer.
n
parallel output lines.
A
control state that leaves the information in the
register unchanged in response to the clock.
14
Slide 15
15
Slide 16
16