Questions in PCIe BAR

Altera_Forum · ‎04-04-2013

1. Why do we need BAR in PCIe?

2. Why do we need multiple BARs in PCIe?

3. How do we choose type of BAR in PCIe? (64 bits/34 bits, Prefetchable/non-prefetchable)

4. With multiple devices (a RAM, a FIFO, a DMA and few I/O Registers) connected to PCIe, how do we know which BAR to connect to which device?

Thank you,

Ranmu

Altera_Forum · ‎04-12-2013

BAR stands for Base Address Memory and you use them as a reference address when you want to access for example a PIO component from your software.

You decide which BAR will be connected to which device. Dont forget that you will use these addresses when you will write your driver.

Altera_Forum · ‎04-12-2013

Dear Tonisss,

Thank you for the reply. It helps me to understand more about PCIe.

Thank you again,

Ranmu