Altera Stratix - Page 501

Altera Corporation 12–15
September 2004 Stratix Device Handbook, Volume 2
Remote System Configuration with Stratix & Stratix GX Devices
read_param N Logic Array
Once
read_param is sampled as a logic high, the busy signal is
asserted. While the parameter is being read, the busy signal remains
asserted, and inputs on
param[] are ignored. Once the busy signal
is deactivated, the next parameter can be read. If this port is left
unconnected, the default value is 0.
write_param N Logic Array This signal is required if you intend on writing parameters to the
remote update block. When driven logic high, the parameter specified
on the
param[] port should be written to the remote update block
with the value on
data_in[]. The number of valid bits on
data_in[] is dependent on the parameter type. This signal is
sampled on the rising edge of clock and should only be asserted for
one clock cycle to prevent the parameter from being re-read on
subsequent clock cycles. Once
write_param is sampled as a logic
high, the busy signal is asserted. While the parameter is being
written, the busy signal remains asserted, and inputs on
param[]
and
data_in[] are ignored. Once the busy signal is deactivated,
the next parameter can be written. This signal is only valid when the
Current_Configuration parameter is factory since parameters
cannot be written in application configurations. If this port is left
unconnected, the default value is 0.
param[2..0] N Logic Array 3-bit bus that selects which parameter should be read or written. If this
port is left unconnected, the default value is 0.
data_in[11..0] N Logic Array This signal is required if you intend on writing parameters to the
remote update block 12-bit bus used when writing parameters, which
specifies the parameter value. The parameter value is requested
using the
param[] input and by driving the write_param signal
logic high, at which point the busy signal goes logic high and the value
of the parameter is captured from this bus. For some parameters, not
all 12-bits will be used in which case only the least significant bits will
be used. This port is ignored if the
Current_Configuration
parameter is set to an application configuration since writing of
parameters is only allowed in the factory configuration. If this port is
left unconnected, the default values is 0.
Note to Ta bl e 1 2 –6 :
(1) Logic array source means that you can drive the port from internal logic or any general-purpose I/O pin.
Table 12–6. Input Ports of the altremote_update Megafunction (Part 2 of 2)
Port Name Required Source Description