MSC8144E Reference Manual, Rev. 3
12-28
Freescale
Semiconductor
DDR SDRAM Memory Controller
ODT_RD_CFG
ODT Read Configuration
DDR1
Always clear to 000.
DDR2
Can be enabled to assert ODT if desired. This
bit can be configured differently depending
upon system topology. However, systems
with only one chip select typically do not use
ODT when issuing reads to the memory.
ODT_WR_CFG
ODT Write Configuration
DDR1
Always clear to 000.
DDR2
Can be enabled to assert ODT if desired. This
bit can be configured differently depending
upon system topology. However, ODT
typically is set to assert the chip select that is
the target of the write (value would be 001).
PDT_PD_EXIT
ODT Power-Down Exit
DDR1 Cleared
to
0000.
DDR2
Set according to the DDR2 specifications for
the memory used. The JEDEC parameter this
applies to is t
axpd
.
PRETOACT
Precharge-to-Activate
Interval
DDR1
Configure according to the specifications for
the memory used (t
rp
)
DDR2
ACTTOPRE
Activate-to-Precharge
Interval
DDR1
Configure according to the specifications for
the memory used (t
ras
)
DDR2
ACTTORW
Activate to Read/Write
Timing
DDR1
Configure according to the specifications for
the memory used (t
rcd
)
DDR2
CASLAT
CAS Latency
DDR1
Configure to the desired
CAS
latency
DDR2
REFREC
Refresh Recovery
DDR1
Configure along with the Extended Refresh
Recovery, to the specifications for the
memory used (t
rfc
)
DDR2
WRREC
Write Recovery
DDR1
Configure according to the specifications for
the memory used (t
wr
)
DDR2
ACTTOACT
Activate A to Activate B
Interval
DDR1
Configure according to the specifications for
the memory used (t
rrd
)
DDR2
WRTORD
Write to Read Interval
DDR1
Configure according to the specifications for
the memory used (t
wrd
)
DDR2
ADD_LAT
Additive Latency
DDR1
Configure to 000
DDR2
Configure to the desired additive latency. This
must be set to a value less than
TIMING_CFG_1[ACTTORW]
WR_LAT
Write Latency
DDR1
Configure to 001.
DDR2
Configure to CAS latency – 1 cycle. For
example, if the CAS latency if 5 cycles, then
configure this field to 100 (4 cycles).
Table 12-14. Programming Differences Between Memory Types (Continued)
Parameter
Description
Differences
Page
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...