All Questions
7
questions
7
votes
3
answers
7k
views
What does "address space" means when talking about IO devices?
The following quote is from this page:
While some CPU manufacturers implement a single address space in their
chips, others decided that peripheral devices are different from
memory and, ...
- 2,039
11
votes
1
answer
14k
views
How does the Base Address Registers (BARs) in a PCI card work?
I am trying to understand how the Base Address Registers (BARs) in a PCI card work, this is how I think they work:
Each function in a PCI card have 6 BAR fields, and each BAR field is
32-bit in size.
...
- 2,039
2
votes
1
answer
273
views
What does "data bus control" mean?
This video mentions the following:
What does it mean for the DMA controller to be granted the data bus control, does that mean the CPU cannot use the bus to access memory and IO devices until the DMA ...
- 2,039
1
vote
3
answers
1k
views
Can the CPU manipulate the pins of an IO port directly?
Based on what I know so far, when you plug an IO device into an IO port (for example, when you plug a printer into a parallel port), the printer will be represented to the CPU as just another RAM chip....
- 247
4
votes
1
answer
5k
views
How data is accessed in Memory-Mapped I/O?
This is an example of Memory-Mapped I/O:
So basically you access the device controller registers through memory.
Now my question is, when you for example write to the memory location that maps to ...
- 247
1
vote
1
answer
318
views
Can an IO device have some memory space or can it only have registers?
I am learning about IO devices, and so far I have only seen examples of IO devices that have registers and no memory space. For example, this is a printer that have three registers and no memory space:...
- 247
3
votes
3
answers
8k
views
Are "Control register" and "Status register" and "Data register" part of the device itself?
I am studying about Memory-Mapped I/O from here. I have read the following:
From the CPU's perspective, an I/O device appears as a set of
special-purpose registers, of three general types:
...
- 247