Altera Embedded Peripherals IP User Manual
Page 141
Each entry in the address translation table also has two address space indication bits, which specify the
type of address space being mapped. If the type of address space being mapped is memory, the bits also
indicate the resulting PCI address is a 32-bit address.
Table 14-4: Address Space Bit Encodings
Address
Space Indicator
(Bits 1:0)
Description
00
Memory space, 32-bit PCI address.
Address bits 63:32 of the translation table entries are ignored.
01
Reserved.
10
I/O space. The address from the translation table process is modified as described
in Configuration and I/O Space Address Modifications table.
11
Configuration space. The address from the translation table process is treated as a
type 1 configuration address and is modified as described in Configuration and I/
O Space Address Modifications table .
If the space indication bits specify configuration or I/O space, subsequent modifications to the PCI
address are performed..
Table 14-5: Configuration and I/O Space Address Modifications
Address Space
Modifications Performed
I/O
Address bits 2:0 are set to point to the first enabled byte according to the
Avalon byte enables. (Bit 2 only needs to be modified when a 64-bit data path
is in use.)
Address bits 31:3 are handled normally.
Configuration
address bits
23:16 == 0
(bus number ==
0)
Address bits 1:0 are set to
00
to indicate a type 0 configuration request.
Address bits 10:2 are passed through as normal.
Address bits 31:11 are set to be a one-hot encoding of the device number field
(15:11) of the address from the translation table. For example, if the device
number is
0x00
, address bit 11 is set to 1 and bits 31:12 are set to 0. If the
device number is
0x01
, address bit 12 is set to 1 and bits 31:13, 11 are set to 0.
Address bits 31:24 of the original PCI address are ignored.
Configuration
address bits
23:16 > 0
(bus number > 0)
Address bits 1:0 are set to
01
to indicate a type 1 configuration request.
Address bits 31:2 are passed through unchanged.
UG-01085
2014.24.07
Avalon-to-PCI Address Translation
14-7
PCI Lite Core
Altera Corporation