Protected Resources And Instructions - Analog Devices ADSP-BF53x Blackfin Reference

User Mode
Table 3-2. Registers Accessible in User Mode
Processor Registers
Data Registers
Pointer Registers
Sequencer and Status Registers

Protected Resources and Instructions

System resources consist of a subset of processor registers, all MMRs, and
a subset of protected instructions. These system and core MMRs are
located starting at address 0xFFC0 0000. This region of memory is pro-
tected from User mode access. Any attempt to access MMR space in User
mode causes an exception.
A list of protected instructions appears in
any of the protected instructions from User mode causes an exception
event.
Table 3-3. Protected Instructions
Instruction
RTI
RTX
RTN
CLI
STI
RAISE
RTE
3-4 ADSP-BF53x/BF56x Blackfin Processor Programming Reference
Register Names
R[7:0], A[1:0]
P[5:0], SP, FP, I[3:0], M[3:0], L[3:0], B[3:0]
RETS, LC[1:0], LT[1:0], LB[1:0], ASTAT, CYCLES,
CYCLES2
Table
Description
Return from Interrupt
Return from Exception
Return from NMI
Disable Interrupts
Enable Interrupts
Force Interrupt/Reset
Return from Emulation
Causes an exception only if executed outside Emulation mode
3-3. Any attempt to issue