EXCEPTION PROCESSING STATE (INTERRUPT PROCESSING)
7 - 16
PROCESSING STATES
MOTOROLA
When an interrupt occurs, the instruction at the interrupt starting address is fetched first.
Because the program flow is directed to a different starting address for each interrupt,
the interrupt structure of the DSP56K can be described as “vectored”. A vectored inter-
rupt structure has low execution overhead. If it is known beforehand that certain inter-
rupts will not be used, those interrupt vector locations can be used for program or data
storage.
7.3.3.1 Hardware Interrupt Sources
There are two types of hardware interrupts in the DSP56K: internal and external. The
internal interrupt sources include all of the on-chip peripheral devices. For further infor-
mation on a device’s internal interrupt sources, see the device’s individual User’s Man-
ual.
The external hardware interrupt sources are the RESET, NMI, IRQA, and IRQB pins on
the program interrupt controller in the Program Control Unit.
The level sensitive RESET interrupt is the highest priority interrupt with an IPL of 3. IRQA
and IRQB can be programmed to one of three priority levels: 0, 1, or 2 - all of which are
maskable. IRQA and IRQB have independent enable control and can be programmed to
be level sensitive or edge sensitive. Since level-sensitive interrupts will not be cleared
automatically when they are serviced, they must be cleared by other means to prevent
multiple interrupts. Edge-sensitive interrupts are latched as pending on the high-to-low
transition of the interrupt input and are automatically cleared when the interrupt is ser-
viced.
Interrupt
Starting Address
IPL
Interrupt Source
$0000
3
Hardware RESET
$0002
3
Stack Error
$0004
3
Trace
$0006
3
SWI
$0008
0 - 2
IRQA
$000A
0 - 2
IRQB
:
:
Vectors available for peripherals
$001E
3
NMI
:
:
Vectors available for peripherals
$003E
3
Illegal Instruction
Table 7-6 Interrupt Sources
Summary of Contents for DSP56K
Page 12: ...xii LIST of TABLES MOTOROLA List of Tables Continued Table Page Number Title Number ...
Page 13: ...MOTOROLA DSP56K FAMILY INTRODUCTION 1 1 SECTION 1 DSP56K FAMILY INTRODUCTION ...
Page 31: ...MOTOROLA DATA ARITHMETIC LOGIC UNIT 3 1 SECTION 3 DATA ARITHMETIC LOGIC UNIT ...
Page 50: ...DATA ALU SUMMARY 3 20 DATA ARITHMETIC LOGIC UNIT MOTOROLA ...
Page 51: ...MOTOROLA ADDRESS GENERATION UNIT 4 1 SECTION 4 ADDRESS GENERATION UNIT ...
Page 77: ...MOTOROLA PROGRAM CONTROL UNIT 5 1 SECTION 5 PROGRAM CONTROL UNIT ...
Page 124: ...INSTRUCTION GROUPS 6 30 INSTRUCTION SET INTRODUCTION MOTOROLA ...
Page 125: ...MOTOROLA PROCESSING STATES 7 1 SECTION 7 PROCESSING STATES STOP WAIT EXCEPTION NORMAL RESET ...
Page 167: ...STOP PROCESSING STATE MOTOROLA PROCESSING STATES 7 43 ...
Page 168: ...STOP PROCESSING STATE 7 44 PROCESSING STATES MOTOROLA ...
Page 169: ...MOTOROLA PORT A 8 1 SECTION 8 PORT A ...
Page 176: ...PORT A INTERFACE 8 8 PORT A MOTOROLA ...
Page 177: ...MOTOROLA PLL CLOCK OSCILLATOR 9 1 SECTION 9 PLL CLOCK OSCILLATOR x x d Φ VCO ...
Page 191: ...10 2 ON CHIP EMULATION OnCE MOTOROLA SECTION 10 ON CHIP EMULATION OnCE ...
Page 218: ...USING THE OnCE MOTOROLA ON CHIP EMULATION OnCE 10 29 ...
Page 604: ...INSTRUCTION ENCODING A 338 INSTRUCTION SET DETAILS MOTOROLA ...
Page 605: ...MOTOROLA BENCHMARK PROGRAMS B 1 APPENDIX B BENCHMARK PROGRAMS T T T T T P1 P3 P2 P4 T T T ...
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