
Table 3-2: Configuration Timing Parameters
Parameter GUI Legal Values Default Values Units
CAS latency cycles 1, 2, 3 3 Cycles
Initialization refresh cycles 1:8 2 Cycles
Issue one refresh command
every
0.0:156.25 15.625 us
Delay after power up, before
initialization
0.0:999.0 100.00 us
Duration of refresh command
(t_rfc)
0.0:700.0 70.0 ns
Duration of precharge
command (t_rp)
0.0:200.0 20.0 ns
ACTIVE to READ or WRITE
delay (t_rcd)
0.0:200.0 20.0 ns
Access time (t_ac) 0.0:999.0 5.5 ns
Write recovery time (t_wr, no
auto precharge)
0.0:140.0 14.0 ns
Interface
The following are top level signals from the SDRAM controller Core
Table 3-3: Clock and Reset Signals
Signal Width Direction Description
clk
1 Input System Clock
rst_n
1 Input System asynchronous reset.
The signal is asserted
asynchronously, but is de-
asserted synchronously after
the rising edge of ssi_clk.
The synchronization must be
provided external to this
component.
UG-01085
2014.24.07
Interface
3-3
Tri-State SDRAM
Altera Corporation
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