
Signal Direction Description
rx_st_sop
Output Indicates that this is the first cycle of the TLP when rx_st_valid
is asserted.
rx_st_valid Output Clocks rx_st_data into the Application Layer. Deasserts within
2 clocks of rx_st_ready deassertion and reasserts within 2 clocks
of rx_st_ready assertion if more data is available to send.
serr_out
Output System Error: This signal only applies to Root Port designs that
report each system error detected, assuming the proper enabling
bits are asserted in the Root Control and Device Control
registers. If enabled, serr_out is asserted for a single clock cycle
when a system error occurs. System errors are described in the
PCI Express Base Specification 2.1 or 3.0 in the Root Control
register.
tl_cfg_add[3:0]
Output Address of the register that has been updated. This signal is an
index indicating which Configuration Space register information
is being driven onto tl_cfg_ctl.
tl_cfg_sts[52:0]
Output Configuration status bits. This information updates every pld_
clk cycle. The following table provides detailed descriptions of
the status bits.
tx_st_ready Output Indicates that the Transaction Layer is ready to accept data for
transmission. The core deasserts this signal to throttle the data
stream. tx_st_ready may be asserted during reset. The Applica‐
tion Layer should wait at least 2 clock cycles after the reset is
released before issuing packets on the Avalon-ST TX interface.
The reset_status signal can also be used to monitor when the
IP core has come out of reset.
If asserted by the Transaction Layer on cycle <n>tx_st_ready ,
then <n + readyLatency> is a ready cycle, during which the
Application Layer may assert tx_st_valid and transfer data.
When tx_st_ready, tx_st_valid and tx_st_data are
registered (the typical case), Altera recommends a readyLatency
of 2 cycles to facilitate timing closure; however, a readyLatency
of 1 cycle is possible. If no other delays are added to the
read-valid latency, the resulting delay corresponds to a readyLa-
tency of 2.
UG-01097_avmm
2014.12.15
Hard IP Status Extension
4-19
64- or 128-Bit Avalon-MM Interface to the Application Layer
Altera Corporation
Send Feedback
Komentáře k této Příručce