INTERRUPTS
11-37
11
11.9.3
Base Interrupt Latency
In many applications, the processor’s instruction mix and cache configuration are known suffi-
ciently well to use typical interrupt latency in calculations of overall system performance. For
example, a timer interrupt may frequently trigger a task switch in a multi-tasking kernel. Base
interrupt latency assumes the following:
•
Single-cycle RISC instruction is interrupted.
•
Frame flush does not occur.
•
Bus queue is empty.
•
Cached interrupt handler.
•
No interaction of faults and interrupts (i.e., a stable system).
Table 11-3
shows the base latencies for all interrupt types, with varying pin sampling and vector
caching options. Note that the 80960JD interrupt latency is approximately 50% less than the
80960JA/JF interrupt latency due to its core clock operating at twice the speed of CLKIN.
The 80960JT is approximately 70% less than the 80960JA/JF and approximately 30% less than the
80960JD, due to its core clock operating at three times the speed of CLKIN.
Table 11-3. Base Interrupt Latency
Interrupt Type
Detection
Option
Vector
Caching
Enabled
Typical
80960JA/JF
Latency
(Bus Clocks)
Typical
80960JD
Latency
(Bus Clocks)
Typical
80960JT (3x)
Latency
(Bus Clocks)
NMI
Fast
Yes
29
14.5
9.7
Debounced
Yes
32
15.5
13.7
Dedicated Mode
XINT[7:0], TINT[1:0]
Fast
Yes
34
17.5
12
No
40+a
21+b
14+c
Debounced
Yes
37
21.5
16.3
No
45+a
26+b
18.3+c
Expanded Mode
XINT[7:0], TINT[1:0]
Debounced
Yes
37
22
16
No
45+a
26+b
18.7+c
Software
NA
Yes
68
35
20+c+d
No
69+a
36.5+b
20+2c+d
Notes:
a = MAX (0,N - 7)
b = MAX (0,N - 3.5)
c = MAX (0, N-2.3)
d = N
where “N” is the number of bus cycles needed to perform a word load.
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 ...
Страница 258: ......
Страница 291: ...9 TRACING AND DEBUGGING ...
Страница 292: ......
Страница 309: ...10 TIMERS ...
Страница 310: ......
Страница 324: ......
Страница 325: ...11 INTERRUPTS ...
Страница 326: ......
Страница 369: ...12 INITIALIZATION AND SYSTEM REQUIREMENTS ...
Страница 370: ......
Страница 412: ......
Страница 413: ...13 MEMORY CONFIGURATION ...
Страница 414: ......
Страница 429: ...14 EXTERNAL BUS ...
Страница 430: ......
Страница 468: ......
Страница 469: ...15 TEST FEATURES ...
Страница 470: ......
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 ...
Страница 516: ......
Страница 523: ...D REGISTER AND DATA STRUCTURES ...
Страница 524: ......
Страница 550: ......
Страница 551: ...GLOSSARY ...
Страница 552: ......
Страница 561: ...INDEX ...
Страница 562: ......
Страница 578: ......