ADSP-BF537 Blackfin Processor Hardware Reference
6-75
External Bus Interface Unit
Exit Self-Refresh Mode
The SDRAM device exits self-refresh mode only when the SDC
receives core or DMA requests. In conjunction with the
SRFS
bit, 2
possibilities are given to exit self-refresh mode:
1. If the
SRFS
bit keeps set before the core/DMA request, the SDC
exits self-refresh mode temporarily for a single request and returns
back to self-refresh mode until a new request is latched.
2. If the
SRFS
bit is cleared before the core/DMA request, the SDC
exits self-refresh mode and returns to auto-refresh mode.
Before exiting self-refresh mode with the
SRFS
bit, be sure to enable
the
CLKOUT
pin (
SCTLE
bit). If this is not done, the SDRAM is
unclocked and will not work properly.
•
External buffering enabled
(
EBUFE
)
With the total I/O width of 16 bits, a maximum of 4x4 bits can be
connected in parallel in order to increase the system’s overall page
size.
To meet overall system timing requirements, systems that employ
several SDRAM devices connected in parallel may require buffer-
ing between the processor and multiple SDRAM devices. This
buffering generally consists of a register and driver.
To meet such timing requirements and to allow intermediary regis-
tration, the SDC supports pipelining of SDRAM address and
control signals.
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 ...