EP4CE30F29C7N Datasheet, PDF (396/488 Pages) Altera Corporation – Cyclone IV Device Handbook, Volume 1

2–22
Chapter 2: Cyclone IV Reset Control and Power Down
Simulation Requirements
The deassertion of the busy signal indicates proper completion of the offset
cancellation process on the receiver channel.
Figure 2–13. Sample Reset Sequence of a Receiver and Transmitter Channels-Receiver CDR in Automatic Lock Mode
with the Optional gxb_powerdown Signal ⁽¹⁾
Reset/Power Down Signals
1 μs
2
3
gxb_powerdown
pll_areset
tx_digitalreset
rx_analogreset
rx_digitalreset
5
6
8
Output Status Signals
busy (3)
pll_locked
rx_freqlocked
1
4
7
t_{LTD_Auto} (2)
Notes to Figure 2–13:
(1) The gxb_powerdown signal must not be asserted during the offset cancellation sequence.
(2) For t_{LTD_Auto} duration, refer to the Cyclone IV Device Datasheet chapter.
(3) The busy signal is asserted and deasserted only during initial power up when offset cancellation occurs. In subsequent reset sequences, the busy
signal is asserted and deasserted only if there is a read or write operation to the ALTGX_RECONFIG megafunction.
Simulation Requirements
The following are simulation requirements:
■ The gxb_powerdown port is optional. In simulation, if the gxb_powerdown port is not
instantiated, you must assert the tx_digitalreset, rx_digitalreset, and
rx_analogreset signals appropriately for correct simulation behavior.
■ If the gxb_powerdown port is instantiated, and the other reset signals are not used,
you must assert the gxb_powerdown signal for at least 1 s for correct simulation
behavior.
■ You can deassert the rx_digitalreset signal immediately after the rx_freqlocked
signal goes high to reduce the simulation run time. It is not necessary to wait for
t_{LTD_Auto} (as suggested in the actual reset sequence).
■ The busy signal is deasserted after about 20 parallel reconfig_clk clock cycles in
order to reduce simulation run time. For silicon behavior in hardware, you can
follow the reset sequences described in the previous pages.
Cyclone IV Device Handbook,
Volume 2
May 2013 Altera Corporation