Definitions
Design
Control Unit (CU) allows CPU operations to be based on external code found in the BIOS, allowing use of components not found in original design.
Arithmetic Logic Unit (ALU) Handles all basic math functions.
Input/Output Unit Sends and receives data from external bus.
Registers
Temporary storage areas used for data manipulation. Rows of switches set to ON or OFF. Registers went from 4 to 64 bits in size.
Codes
Machine code is sent as binary numbers on the data bus. Unique to every CPU.
Clock
Used to synchronize operations so that internal commands are executed in the proper order. Each pulse of the crystal represents one cycle. All switching activity occurs on the pulse. All commands need at least 2 pulses (cycles) some need hundreds.
Clock Speed
Amount of time clock pulses per second. Measured in Megahertz (MHz). A CPUs clock rate represents the maximum speed at which it will operate reliably. Overclocking old chips could lead to failure.
Data bus (External Bus)
Main conduit for moving information to and from the CPU and data handling components inside the computer.
0 volts = Off
5 volts = On
Address Bus
Ram is a temporary storage area used by the CPU to complete processing functions. The address bus transmits information describing memory locations to the memory controller. The larger the address bus the more memory that can be addresses. Early address busses had 8 wires (8 bits).
Memory Controller
Cpu accesses memory through the memory controller. If memory is not tuned to the max CPU speed, extra cycles (wait states) are needed until memory is ready for next part of operation.
Control Unit (CU) allows CPU operations to be based on external code found in the BIOS, allowing use of components not found in original design.
Arithmetic Logic Unit (ALU) Handles all basic math functions.
Input/Output Unit Sends and receives data from external bus.
Registers
Temporary storage areas used for data manipulation. Rows of switches set to ON or OFF. Registers went from 4 to 64 bits in size.
Codes
Machine code is sent as binary numbers on the data bus. Unique to every CPU.
Clock
Used to synchronize operations so that internal commands are executed in the proper order. Each pulse of the crystal represents one cycle. All switching activity occurs on the pulse. All commands need at least 2 pulses (cycles) some need hundreds.
Clock Speed
Amount of time clock pulses per second. Measured in Megahertz (MHz). A CPUs clock rate represents the maximum speed at which it will operate reliably. Overclocking old chips could lead to failure.
Data bus (External Bus)
Main conduit for moving information to and from the CPU and data handling components inside the computer.
0 volts = Off
5 volts = On
Address Bus
Ram is a temporary storage area used by the CPU to complete processing functions. The address bus transmits information describing memory locations to the memory controller. The larger the address bus the more memory that can be addresses. Early address busses had 8 wires (8 bits).
Memory Controller
Cpu accesses memory through the memory controller. If memory is not tuned to the max CPU speed, extra cycles (wait states) are needed until memory is ready for next part of operation.
