Altera Stratix V Avalon-ST User Manual
Page 62

Signal
Direction
Description
dlup
Output
When asserted, indicates that the Hard IP block is in the Data
Link Control and Management State Machine (DLCMSM) DL_
Up state.
dlup_exit
Output
This signal is asserted low for one
pld_clk
cycle when the IP
core exits the DLCMSM DL_Up state, indicating that the Data
Link Layer has lost communication with the other end of the
PCIe link and left the Up state. When this pulse is asserted, the
Application Layer should generate an internal reset signal that is
asserted for at least 32 cycles.
ev128ns
Output
Asserted every 128 ns to create a time base aligned activity.
ev1us
Output
Asserted every 1 µs to create a time base aligned activity.
hotrst_exit
Output
Hot reset exit. This signal is asserted for 1 clock cycle when the
LTSSM exits the hot reset state. This signal should cause the
Application Layer to be reset. This signal is active low. When this
pulse is asserted, the Application Layer should generate an
internal reset signal that is asserted for at least 32 cycles.
int_status[3:0]
Output
These signals drive legacy interrupts to the Application Layer as
follows:
• int_status[0]: interrupt signal A
• int_status[1]: interrupt signal B
• int_status[2]: interrupt signal C
• int_status[3]: interrupt signal D
l2_exit
Output
L2 exit. This signal is active low and otherwise remains high. It is
asserted for one cycle (changing value from 1 to 0 and back to 1)
after the LTSSM transitions from l2.idle to detect. When this
pulse is asserted, the Application Layer should generate an
internal reset signal that is asserted for at least 32 cycles.
lane_act[3:0]
Output
Lane Active Mode: This signal indicates the number of lanes that
configured during link training. The following encodings are
defined:
• 4’b0001: 1 lane
• 4’b0010: 2 lanes
• 4’b0100: 4 lanes
• 4’b1000: 8 lanes
UG-01097_sriov
2014.12.15
Reset, Status, and Link Training Signals
4-27
Interfaces and Signal Descriptions
Altera Corporation