
5–30 Chapter 5: IP Core Interfaces
Avalon-ST Interface
IP Compiler for PCI Express User Guide August 2014 Altera Corporation
The configuration space signals provide access to some of the control and status
information available in the configuration space registers; these signals provide access
to unused registers that are labeled reserved in the PCI Express Base Specification
Revision 2.0. This interface is synchronous to
core_clk
. To access the configuration
space from the application layer, you must synchronize to the application layer clock.
Table 5–13 describes the configuration space interface and hot plug signals that are
available in the hard IP implementation. Refer to Chapter 6 of the PCI Express Base
Specification Revision 2.0 for more information about the hot plug signals.
Table 5–13. Configuration Space Signals (Hard IP Implementation) (Part 1 of 2)
Signal Width Dir Description
tl_cfg_add
40
Address of the register that has been updated. This address space is described in
Table 5–14 on page 5–33. The information updates every 8
core_clks
along with
tl_cfg_ctl
.
tl_cfg_ctl
32 0
The
tl_cfg_ctl
signal is multiplexed and contains the contents of the configuration
space registers shown in Table 5–14 on page 5–33. This register carries data that
updates every 8
core_clk
cycles.
tl_cfg_ctl_wr
10
Write signal. This signal toggles when
tl_cfg_ctl
has been updated (every 8
core_clk
cycles). The toggle edge marks where the
tl_cfg_ctl
data changes. You
can use this edge as a reference to determine when the data is safe to sample.
tl_cfg_sts
53 0
Configuration status bits. This information updates every 8
core_clk
cycles. The
cfg_sts
group consists of (from MSB to LSB):
tl_cfg_sts[52:49]
=
cfg_devcsr[19:16]
error detection signal as follows:
[
correctable
error
reporting,
enable, non-fatal
error
reporting
enable,
fatal error reporting enable,
unsupported request
reporting enable
]
tl_cfg_sts[48]
=
cfg_slotcsr[24]
Data link layer state changed
tl_cfg_sts[47]
=
cfg_slotcsr[20]
Command completed
tl_cfg_sts[46:31]
=
cfg_linkcsr[31:16]
Link status bits
tl_cfg_sts[30]
=
cfg_link2csr[16]
Current de-emphasis level.
cfg_link2csr[31:17]
are reserved per the PCIe Specification and are not
available on
tl_cfg_sts
bus
tl_cfg_sts[29:25]
=
cfg_prmcsr[31:27]
5 primary command status error bits
tl_cfg_sts[24]
=
cfg_prmcsr[24]
6th primary command status error bit
tl_cfg_sts[23:6]
=
cfg_rootcsr[25:8]
PME bits
tl_cfg_sts[5:1]
=
cfg_seccsr[31:27]
5 secondary command status error bits
tl_cfg_sts[0]
=
cfg_seccsr[24]
6th secondary command status error bit
tl_cfg_sts_wr
10
Write signal. This signal toggles when
tl_cfg_sts
has been updated (every 8
core_clk
cycles). The toggle marks the edge where
tl_cfg_sts
data changes. You
can use this edge as a reference to determine when the data is safe to sample.
Comentarios a estos manuales