SDRAM Controller (SDC)
18-44
ADSP-BF535 Blackfin Processor Hardware Reference
If the system uses SDRAM, but the clock load is minimal,
SCTLE
should be
1 and
SCK1E
should be 0. This setting enables the
SCLK[0]
pin and all
related SDRAM control pins, but disables (holds low) the second clock
pin
SCLK[1]
.
If the system uses SDRAM and the clock loading is high, both
SCTLE
and
SCK1E
should be set to 1. This setting enables
SCLK[0]
,
SCLK[1]
, and all
SDRAM control pins. In this configuration,
SCLK[0]
and
SCLK[1]
should
each share half of the clock load.
If an access occurs to the SDRAM address space while
SCTLE
is 0, the
access generates an internal bus error, and the access does not occur exter-
nally.
For more information, see “Error Detection” on page 18-8.
With
careful software control, the
SCTLE
and
SCK1E
bits can be used in conjunc-
tion with Self-Refresh mode to further lower the power consumption.
However,
SCTLE
must remain enabled at all times when the SDC is needed
to generate Auto-Refresh commands to SDRAM.
Entering and Exiting Self-Refresh Mode (SRFS)
The SDC supports SDRAM Self-Refresh mode. In Self-Refresh mode, the
SDRAM performs refresh operations internally—without external con-
trol—reducing the SDRAM’s power consumption.
The
SRFS
bit in
EBIU_SDGCTL
enables the start of Self-Refresh mode:
SRFS = 0
No effect
SRFS = 1
Start Self-Refresh mode
When
SRFS
is set to 1, once the SDC enters an idle state it issues a Pre-
charge command if necessary and then issues a Self-Refresh command. If
an internal access is pending, the SDC delays issuing the Self-Refresh
command until it completes the pending SDRAM access and any subse-
quent pending access requests. Refer to
“SDC Commands” on page 18-75
for more information.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...