ADSP-BF535 Blackfin Processor Hardware Reference
5-5
Data Address Generators
Frame and Stack Pointers
In many respects, the Frame and Stack Pointer registers perform like the
other P-registers,
P[5:0]
. They can act as general pointers in any of the
load/store instructions. For example,
R1 = B[SP] (Z)
. However,
FP
and
SP
have additional functionality.
The Stack Pointer registers include:
• a User Stack Pointer (
USP
in Supervisor mode,
SP
in User mode)
• a Supervisor Stack Pointer (
SP
in Supervisor mode)
The User Stack Pointer register and the Supervisor Stack Pointer register
are accessed using the register alias
SP
. Depending on the current proces-
sor operating mode, only one of these registers is active and accessible as
SP
:
• In User mode, any reference to
SP
(for example, stack pop
R0 = [ SP++ ] ;
) implicitly uses the
USP
as the effective address.
• In Supervisor mode, the same reference to
SP
(for example,
R0 = [ SP++ ] ;
) implicitly uses the Supervisor Stack Pointer as
the effective address.
• To manipulate the User Stack Pointer for code running in Supervi-
sor mode, use the register alias
USP
. When in Supervisor mode, a
register move from
USP
(for example,
R0 = USP ;
) moves the cur-
rent User Stack Pointer into
R0
. The register alias
USP
can only be
used in Supervisor mode.
Some load/store instructions use
FP
and
SP
exclusively, for example:
•
FP
-indexed load/store, which extends the addressing range for
16-bit encoded load/stores
• Stack push/pop instructions
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...