2–164
Altera Corporation
Stratix II GX Device Handbook, Volume 2
October 2007
Native Modes
Figure 2–118
shows the NFRI_PLD_logic state machine.
Figure 2–118. NFRI_PLD_logic State Machine
Notes to
Figure 2–118
:
(1)
Forward the ALT2GXB value to the
NFRI_PLD_logic
output. For example, forward the pipedatavalid value from
the ALT2GXB to the
pipedatavalid_PLD
for use in user logic.
(2)
After the
3.2us_timer
expires, it is important to reset
rx_digitalreset
for two parallel clock cycles. For
example, now that correct data is coming through, the FIFO should be cleared and the pointers reset to the middle.
Following this reset, look for the FTS ordered set. For other cases to assert
rx_diditalreset
, refer to
“Reset
Sequence for PIPE Mode” on page 2–218
.
Start
Wait for EIOS or
falling edge of
rx_signaldetect.
EIOS or falling edge detected.
Assert
pipeeleidle_PLD.
De-assert
pipedatavalid_PLD.
Wait 250 ns and then wait until
rx_signaldetect is asserted.
rx_signaldetect asserted.
Start 3.2 us and 4 us timers.
Wait for the 3.2 us timer to expire
and ignore
rx_signaldetect.
3.2 us timer expires.
Assert
rx_digitalreset for two
parallel clock cycles
(2).
Wait for
rx_signaldetect
de-asserts, or an FTS Ordered
Set or the 4 us timer expires.
One FTS ordered set received
and the 4 us timer not expired.
Assert
pipedatavalid_PLD.
Set
pipeeleidle_PLD to
pipeeleidle value
(1).
Wait for the 4 us timer to expire or
rx_signaldetect de-asserts.
"4 us timer expires" or
"
rx_signaldetect de-asserts
and 4 us timer not expired".
"4 us timer expires" or
"
rx_signaldetect de-asserts
and 4 us timer not expired".
Reset 3.2 us and 4 us timers.
Set
pipeeleidle_PLD to
pipeeleidle value
(1).
Set
pipedatavalid_PLD to
pipedatavalid value
(1).