SDC Register Definitions
6-74
ADSP-BF537 Blackfin Processor Hardware Reference
•
Self-refresh setting
(
SRFS
)
The
SRFS
and
SCTLE
bits work together in
EBIU_SDGCTL
for
self-refresh control:
•
SRFS = 0
Disable self-refresh mode
•
SRFS = 1
Enter self-refresh mode
When
SRFS
is set to 1, self-refresh mode is triggered. Once the
SDC completes any active transfers, the SDC executes a sequence
of commands to put the SDRAM into self-refresh mode.
When the device comes out of reset, the
SCKE
pin is driven high. If
it is necessary to enter self-refresh mode after reset, program
SRFS
=
1
.
Enter Self-Refresh Mode
When
SRFS
is set to 1, once the SDC enters an idle state it issues a
precharge all command and then issues a self-refresh entry com-
mand. If an internal access is pending, the SDC delays issuing the
self-refresh entry command until it completes the pending
SDRAM access and any subsequent pending access requests.
Once the SDRAM device enters into self-refresh mode, the
SDRAM controller asserts the
SDSRA
bit in the SDRAM control
status register (
EBIU_SDSTAT
).
Note once the
SRFS
bit is set to 1, the SDC enters self-refresh mode
when it finishes pending accesses. There is no way to cancel the
entry into self-refresh mode.
Before disabling the
CLKOUT
pin with the
SCTLE
bit, be sure to place
the SDC in self-refresh mode (
SRFS
bit). If this is not done, the
SDRAM is unclocked and will not work properly.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...