2–162
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Native Modes
Sequence to Generate pipeelecidle_PLD and pipedatavalid_PLD
Signals
To generate the
pipeelecidle_PLD
and
pipedatavalid_PLD
signals, follow these steps:
1.
When you detect EIOS ordered set or the falling edge of
rx_signaldetect
:
●
assert
pipeelecidle_PLD
●
deassert
pipedatavalid_PLD
2.
Wait 250 ns. This is the minimum time required for
rx_signaldetect
to get deasserted when there is no valid signal
at the receive input.
3.
Wait for
rx_signaldetect
to get asserted.
4.
Start the
3.2us_timer
and
4us_timer
. Ignore
rx_signaldetect
during this step.
5.
Wait for the
3.2us_timer
to expire. Ignore
rx-signaldetect
during this step.
6.
If one FTS ordered set is received and the
4us_timer
has NOT
expired:
●
Set
pipeelecidle_PLD
to the pipeelecidle value (that is,
forward the pipeelecidle value from the ALT2GXB to the user
logic).
●
Assert
pipedatavalid_PLD
.
●
Reset and pause the
3.2us_timer
and
4us_timer
.
●
Return to Step 1.
7.
If
rx_signaldetect
gets deasserted and the
4us_timer
has
NOT expired:
●
Reset and pause the
3.2us_timer
and
4us_timer
.
●
Set
pipeelecidle_PLD
to the pipeelecidle value (that is,
forward the pipeelecidle value from the ALT2GXB to the user
logic). Set the
pipedatavalid_PLD
to the pipedatavalid value
(that is, forward the pipedatavalid value from the ALT2GXB to
the user logic).
●
Return to Step 1.