ADSP-BF537 Blackfin Processor Hardware Reference
6-73
External Bus Interface Unit
If the
PSM
bit is set to 0, the SDC command sequence is:
1. Precharge all
2. 8 auto-refresh cycles
3. Mode register set
•
Powerup sequence start enable
(
PSSE
)
The
PSM
and
PSSE
bits work together to specify and trigger an
SDRAM powerup (initialization) sequence. Two events must occur
before the SDC does the SDRAM powerup sequence:
• The
PSSE
bit must be set to 1 to enable the SDRAM pow-
erup sequence.
• A read or write access must be done to enabled SDRAM
address space in order to have the external bus granted to
the SDC so that the SDRAM powerup sequence may occur.
The SDRAM powerup sequence occurs and is followed immedi-
ately by the read or write transfer to SDRAM that was used to
trigger the SDRAM powerup sequence. Note there is a latency for
this first access to SDRAM because the SDRAM powerup sequence
takes many cycles to complete.
L
Before executing the SDC powerup sequence, ensure that the
SDRAM receives stable power and is clocked for the proper
amount of time, as specified by the SDRAM specification.
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 ...