ppc460ex Applied Micro Circuits Corporation (AMCC), ppc460ex Datasheet - Page 89

• Manufacturer Part Number: ppc460ex
• Description: Powerpc 460ex Embedded Processor
• Manufacturer: Applied Micro Circuits Corporation (AMCC)

Revision 1.12 – July 17, 2008
DDR SDRAM Write Operation
The rising edge of MemClkOut aligns with the first rising edge of the DQS signal on writes. The following data is
generated by means of simulation and includes logic, driver, package RLC, and lengths. Values are calculated
over best case and worst case processes with speed, junction temperature, and voltage as follows:
Note: In the following tables and timing diagrams, minimum values are measured under best case conditions and
maximum values are measured under worst case conditions. The timing numbers in the following sections are
obtained using a simulation that assumes a model as shown in Figure 9.
The following diagram illustrates the relationship among the signals involved with a DDR write operation.
Figure 10. DDR SDRAM Write Cycle Timing
Note: The timing data in the following tables is based on simulation runs using Einstimer.
AMCC Proprietary
Table 21. DDR SDRAM Write Operation Conditions
Preliminary Data Sheet
Worst
Case
Best
MemClkOut
T
T
T
T
T
SA
SD
HD
HA
DS
MemData
PLB Clk
= Setup time for address and command signals to MemClkOut
= Setup time for data signals (minimum time data is valid before rising/falling edge of DSQ)
= Hold time for data signals (minimum time data is valid after rising/falling edge of DSQ)
= Hold time for address and command signals from MemClkOut
= Delay from rising/falling edge of clock to the rising/falling edge of DQS
DQS
Addr/Cmd
Process Speed
Slow
Fast
T
SA
T
HA
T
T
SD
DS
T
HD
Junction Temperature (°C)
460EX – PPC460EX Embedded Processor
T
DS
+105
−40
T
SD
T
HD
Voltage (V)
+1.3
+1.2
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