User Mode - Analog Devices ADSP-TS101 TigerSHARC Hardware Reference Manual

Normally when the TigerSHARC processor is reset (via hardware or soft-
ware), it is idle. It exits the idle state to a running state when an interrupt
is issued. The interrupt puts the TigerSHARC processor into supervisor
mode.
If the bit in
NMOD
leaving an interrupt routine (unless it is nested inside another interrupt
routine).

User Mode

The user mode operation is used for algorithms and control code that does
not require the manipulation of system resources. Many system resources
are not accessible in user mode. If the TigerSHARC processor attempts to
access these resources, an exception occurs.
User mode is often used when running code out of an operating system.
The operating system kernel runs in supervisor mode, but the user code is
restricted to user mode.
The registers that may be accessed by core program in user mode are:
• Groups 0x00 to 0x09 – Compute block registers
• Groups 0x0C to 0x0F – IALU registers
• Sequencer registers –
Static Flag register (
All other registers cannot be written by the core program in user mode. An
attempt to write to a protected register causes an exception. These regis-
ters can still be accessed by another master (DMA, external host, and so
on).
ADSP-TS101 TigerSHARC Processor
Hardware Reference
is cleared, the processor enters user mode after
SQCTL
, Loop counters
CJMP
)
SFREG
Core Controls
and , and the
LC0 LC1
3-5