INSTRUCTION SET REFERENCE
6-103
6
6.2.61
spanbit
Mnemonic:
spanbit
Span Over Bit
Format:
spanbit
src,
dst
reg/lit
reg
Description:
Searches src value for the most significant clear bit (0 bit). When a most
significant 0 bit is found, its bit number is stored in dst and condition code is
set to 010
2
. When src value is all 1’s, all 1’s are stored in dst and condition
code is set to 000
2
.
Action:
dst = 0xFFFFFFFF;
AC.cc = 000
2
;
for(i = 31; i > = 0; i--)
{
if((src1 & 2**i) == 0))
{
dst = i;
AC.cc = 010
2
;
break;
}
}
Faults:
STANDARD Refer
to
section 6.1.6, “Faults” (pg. 6-5)
.
Example:
# Assume r2 is not 0xffffffff
spanbit r2, r9
# r9
=
bit number of most-
# significant clear bit in r2;
# AC.cc
=
010
2
Opcode:
spanbit
640H
REG
See Also:
scanbit
Side Effects:
Sets the condition code in the arithmetic controls.
Содержание i960 Jx
Страница 1: ...Release Date December 1997 Order Number 272483 002 i960 Jx Microprocessor Developer s Manual ...
Страница 24: ......
Страница 25: ...1 INTRODUCTION ...
Страница 26: ......
Страница 35: ...2 DATA TYPES AND MEMORY ADDRESSING MODES ...
Страница 36: ......
Страница 46: ......
Страница 47: ...3 PROGRAMMING ENVIRONMENT ...
Страница 48: ......
Страница 73: ...4 CACHE AND ON CHIP DATA RAM ...
Страница 74: ......
Страница 85: ...5 INSTRUCTION SET OVERVIEW ...
Страница 86: ......
Страница 111: ...6 INSTRUCTION SET REFERENCE ...
Страница 112: ......
Страница 195: ...INSTRUCTION SET REFERENCE 6 83 6 Opcode mov 5CCH REG movl 5DCH REG movt 5ECH REG movq 5FCH REG See Also LOAD STORE lda ...
Страница 233: ...7 PROCEDURE CALLS ...
Страница 234: ......
Страница 256: ......
Страница 257: ...8 FAULTS ...
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Страница 291: ...9 TRACING AND DEBUGGING ...
Страница 292: ......
Страница 309: ...10 TIMERS ...
Страница 310: ......
Страница 324: ......
Страница 325: ...11 INTERRUPTS ...
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Страница 369: ...12 INITIALIZATION AND SYSTEM REQUIREMENTS ...
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Страница 412: ......
Страница 413: ...13 MEMORY CONFIGURATION ...
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Страница 429: ...14 EXTERNAL BUS ...
Страница 430: ......
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Страница 469: ...15 TEST FEATURES ...
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Страница 493: ...A CONSIDERATIONS FOR WRITING PORTABLE CODE ...
Страница 494: ......
Страница 502: ......
Страница 503: ...B OPCODES AND EXECUTION TIMES ...
Страница 504: ......
Страница 515: ...C MACHINE LEVEL INSTRUCTION FORMATS ...
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Страница 523: ...D REGISTER AND DATA STRUCTURES ...
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Страница 550: ......
Страница 551: ...GLOSSARY ...
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Страница 561: ...INDEX ...
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