Direct memory access performed by a separate module

Direct Memory Access
Performed by a separate module on the system bus or incorporated into
an I/O module
When the processor wishes to read or write data it issues a command to
the DMA module containing:
Whether a read or write is requested
The address of the I/O device involved
The starting location in memory to read/write
The number of words to be read/written
Transfers the entire block of data directly to and from memory without
going through the processor. Processor is involved only at the beginning
and end of the transfer. Processor executes more slowly during a transfer
when processor access to the bus is required. More efficient than
interrupt-driven or programmed I/O
Labs
- Cmd window commands:
Winsat formal – runs the System Assessment Tool
- DHCP (Dynamic Host Configuration Protocol) - A DHCP Server is a
network server that automatically provides and assigns IP addresses,
default gateways and other network parameters to client devices. It
relies on the standard protocol known as Dynamic Host Configuration
Protocol or DHCP to respond to broadcast queries by clients.
- LSM (Local Session Manager) - The lsm.exe, Local Session Manager
Service is a part of Windows operating system, included by Microsoft.
lsm.exe process works in the collaboration of System Management
task and its main function is to manage the connections related to
servers on the hosted machines

CSIS 2260 – Winter 2020
- SPOOLER - A program that controls spooling -- putting jobs on a queue
and taking them off one at a time.
Noteboo
k 01.10
- Program Status Word (PSW)
The Program Status Word or PSW is a collection of data 8 bytes (or 64
bits) long, maintained by the operating system. It keeps track of the
current state of the system. program status word (PSW) A collection of
information that encapsulates the basic execution state of a program at
any instant. It permits an interrupted process to resume operation after
the interrupt has been handled.
- CPU Consists of:
- PC – Progoram counter
- IR – Instruction Register
- MAR – Memory Address Register
- MBR – Memory Buffer Register
- I/OAR – input/output Address Register
- I/OBR – Input/output Buffer Register
Noteboo
k
01.17
- The program counter is responsible for storing the next instruction
- “Word” is what the CPU fetches from memory, it is stored in 16 bits
- Registers are small pieces of memory that store data, they are almost
as fast the CPU
- Buffer is responsible for the rate mismatch
- GPU (Graphics Processing Unit) divides the image in a grid, are used
for deep learning and other fast software technologies, usually dealt in
arrays, has a lot of the image rendering requirements that the CPU
can’t handle or isn’t as fast. Can be used to mine crypto currency.
- DSP is a specialized chip set that can be used to support encryption
and security
- Opcode: In computing, an opcode is the portion of a machine language
instruction that specifies the operation to be performed.