How DMA and PCIe play together?
up vote
1
down vote
favorite
in a PCIe configuration, devices have dedicated addresses and they send data in Peer-to-Peer mode to each other - every device can write when it wills and the switches take care to correctly pass data forward. There is no need to have a "bus master", which decides when and how data will be transmitted.
How does DMA come into play in such configuration? For me it seems that DMA is an outdated feature, which is not needed in a PCIe configuration. Every device can send data to the main memory, or read from it - obviously the main memory will always be the "slave" in such operations.
Or is there some other functionality of DMA, which I am missing?
Thank you in advance!
dma pci-e
asked Nov 18 at 13:40
Emerson Fittipaldi
162
add a comment |
up vote
1
down vote
favorite
in a PCIe configuration, devices have dedicated addresses and they send data in Peer-to-Peer mode to each other - every device can write when it wills and the switches take care to correctly pass data forward. There is no need to have a "bus master", which decides when and how data will be transmitted.
How does DMA come into play in such configuration? For me it seems that DMA is an outdated feature, which is not needed in a PCIe configuration. Every device can send data to the main memory, or read from it - obviously the main memory will always be the "slave" in such operations.
Or is there some other functionality of DMA, which I am missing?
Thank you in advance!
dma pci-e
asked Nov 18 at 13:40
Emerson Fittipaldi
162
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
in a PCIe configuration, devices have dedicated addresses and they send data in Peer-to-Peer mode to each other - every device can write when it wills and the switches take care to correctly pass data forward. There is no need to have a "bus master", which decides when and how data will be transmitted.
How does DMA come into play in such configuration? For me it seems that DMA is an outdated feature, which is not needed in a PCIe configuration. Every device can send data to the main memory, or read from it - obviously the main memory will always be the "slave" in such operations.
Or is there some other functionality of DMA, which I am missing?
Thank you in advance!
dma pci-e
asked Nov 18 at 13:40
Emerson Fittipaldi
162
in a PCIe configuration, devices have dedicated addresses and they send data in Peer-to-Peer mode to each other - every device can write when it wills and the switches take care to correctly pass data forward. There is no need to have a "bus master", which decides when and how data will be transmitted.
How does DMA come into play in such configuration? For me it seems that DMA is an outdated feature, which is not needed in a PCIe configuration. Every device can send data to the main memory, or read from it - obviously the main memory will always be the "slave" in such operations.
Or is there some other functionality of DMA, which I am missing?
Thank you in advance!
dma pci-e
dma pci-e
asked Nov 18 at 13:40
Emerson Fittipaldi
162
asked Nov 18 at 13:40
Emerson Fittipaldi
162
asked Nov 18 at 13:40
Emerson Fittipaldi
162
asked Nov 18 at 13:40
Emerson Fittipaldi
162
asked Nov 18 at 13:40
Emerson Fittipaldi
162
162
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59
add a comment |
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59
add a comment |
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53361506%2fhow-dma-and-pcie-play-together%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
When a PCI device reads or writes main memory, that is DMA.
– prl
Nov 18 at 16:54
Sometimes a PCI device is called a “DMA engine” when reading/writing main memory is its only purpose, for example en.wikipedia.org/wiki/I/O_Acceleration_Technology.
– prl
Nov 18 at 16:59