MSC8254_11 Datasheet, PDF (61/68 Pages) Freescale Semiconductor, Inc – Quad-Core Digital Signal Processor

Hardware Design Considerations
3.5.1.2 DDR Interface Is Used With 32-Bit DDR Memory Only
Table 41 lists unused pin connection when using 32-bit DDR memory. The 32 most significant data lines are not used.
Table 41. Connectivity of DDR Related Pins When Using 32-bit DDR Memory Only
Signal Name
Pin Connection
MDQ[31–0]
MDQ[63–32]
in use
NC
MDQS[3–0]
MDQS[7–4]
in use
NC
MDQS[3–0]
MDQS[7–4]
in use
NC
MA[15–0]
MCK[2–0]
MCK[2–0]
in use
in use
in use
MCS[1–0]
MDM[3–0]
MDM[7–4]
in use
in use
NC
MBA[2–0]
MCAS
in use
in use
MCKE[1–0]
MODT[1–0]
MMDIC[1–0]
MRAS
MWE
in use
in use
in use
in use
in use
MVREF
GVDD1/GVDD2
in use
in use
Notes: 1. For the signals listed in this table, the initial M stands for M1 or M2 depending on which DDR controller is not used.
2. For MSC8254 Revision 1 silicon, these pins were connected to GND (or VDD). For newer revisions of the MSC8254,
connecting these pins to GND increases device power consumption.
3.5.1.3 ECC Unused Pin Connections
When the error code correction mechanism is not used in any 32- or 64-bit DDR configuration, refer to Table 42 to determine
the correct pin connections.
Table 42. Connectivity of Unused ECC Mechanism Pins
Signal Name
Pin connection
MECC[7–0]
NC
MDM8
NC
MDQS8
NC
MDQS8
NC
Notes: 1. For the signals listed in this table, the initial M stands for M1 or M2 depending on which DDR controller is not used.
2. For MSC8254 Revision 1 silicon, these pins were connected to GND (or VDD). For newer revisions of the MSC8254,
connecting these pins to GND increases device power consumption.
MSC8254 Quad-Core Digital Signal Processor Data Sheet, Rev. 6
Freescale Semiconductor
61