NORMAL PROCESSING STATE
7 - 6
PROCESSING STATES
MOTOROLA
second instruction of the downloaded code at P:$0001 of the internal RAM. However, the
ANDI instruction allows the OMR to be changed before the JMP instruction uses it, and
the JMP fetches P:$0000 of the internal RAM.
Case 4:
An interrupt has two additional control cycles that are executed in the interrupt
controller concurrently with the fetch, decode, and execute cycles (see Section 7.3 and
Figure 7-4). During these two control cycles, the interrupt is arbitrated by comparing the
interrupt mask level with the interrupt priority level (IPL) of the interrupt and allowing or
disallowing the interrupt. Therefore, if the interrupt mask is changed after an interrupt is
arbitrated and accepted as pending but before the interrupt is executed, the interrupt will
be executed, regardless of what the mask was changed to. The following examples show
that the old interrupt mask is in effect for up to four additional instruction cycles after the
interrupt mask is changed. All instructions shown in the examples here are one-word in-
structions; however, one two-word instruction can replace two one-word instructions
except where noted.
1. Program flow with no interrupts after interrupts are disabled:
•
•
ORI #03,MR
;Disable interrupts
INST 1
INST 2
INST 3
INST 4
•
•
2. The four possible variations in program flow that may occur after interrupts are
disabled:
•
•
•
•
•
•
•
•
ORI #03,MR
ORI #03,MR
ORI #03,MR
ORI #03,MR
II (See Note 2)
INST 1
INST 1
INST 1
II+1
II
INST 2
INST 2
INST 1
II+1
ll
INST 3 (See Note 1)
INST 2
INST 2
II+1
ll
INST 3
INST 3
INST 3
II+1
INST 4
INST 4
INST 4
INST 4
•
•
•
•
•
•
•
•
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 ...
Page 609: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 5 ...
Page 611: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 7 ...
Page 613: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 9 ...
Page 615: ...BENCHMARK PROGRAMS MOTOROLA BENCHMARK PROGRAMS B 11 ...