Atmel AT32UC3L016, Руководство пользователя

Страница: 27 / 88

27
32099DS–06/2010
AT32UC3L016/32/64
4.5 Exceptions and Interrupts
In the AVR32 architecture, events are used as a common term for exceptions and interrupts.
AVR32UC incorporates a powerful event handling scheme. The different event sources, like Ille-
gal Op-code and interrupt requests, have different priority levels, ensuring a well-defined
behavior when multiple events are received simultaneously. Additionally, pending events of a
higher priority class may preempt handling of ongoing events of a lower priority class.
When an event occurs, the execution of the instruction stream is halted, and execution is passed
to an event handler at an address specified in
Table 4-4 on page 31 . Most of the handlers are
placed sequentially in the code space starting at the address specified by EVBA, with four bytes
between each handler. This gives ample space for a jump instruction to be placed there, jump-
ing to the event routine itself. A few critical handlers have larger spacing between them, allowing
the entire event routine to be placed directly at the address specified by the EVBA-relative offset
generated by hardware. All interrupt sources have autovectored interrupt service routine (ISR)
addresses. This allows the interrupt controller to directly specify the ISR address as an address
90 360 MPUPSR2 MPU Privilege Select Register region 2
91 364 MPUPSR3 MPU Privilege Select Register region 3
92 368 MPUPSR4 MPU Privilege Select Register region 4
93 372 MPUPSR5 MPU Privilege Select Register region 5
94 376 MPUPSR6 MPU Privilege Select Register region 6
95 380 MPUPSR7 MPU Privilege Select Register region 7
96 384 MPUCRA Unused in this version of AVR32UC
97 388 MPUCRB Unused in this version of AVR32UC
98 392 MPUBRA Unused in this version of AVR32UC
99 396 MPUBRB Unused in this version of AVR32UC
100 400 MPUAPRA MPU Access Permission Register A
101 404 MPUAPRB MPU Access Permission Register B
102 408 MPUCR MPU Control Register
103 412 SS_STATUS Secure State Status Register
104 416 SS_ADRF Secure State Address Flash Register
105 420 SS_ADRR Secure State Address RAM Register
106 424 SS_ADR0 Secure State Address 0 Register
107 428 SS_ADR1 Secure State Address 1 Register
108 432 SS_SP_SYS Secure State Stack Pointer System Register
109 436 SS_SP_APP Secure State Stack Pointer Application Register
110 440 SS_RAR Secure State Return Address Register
111 444 SS_RSR Secure State Return Status Register
112-191 448-764 Reserved Reserved for future use
192-255 768-1020 IMPL IMPLEMENTATION DEFINED
Table 4-3. System Registers (Continued)
Reg # Address Name Function