參數(shù)資料
型號(hào): COP8SAC740N9
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 微控制器/微處理器
英文描述: 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
中文描述: 8-BIT, OTPROM, 10 MHz, MICROCONTROLLER, PDIP40
封裝: DIP-40
文件頁數(shù): 29/60頁
文件大?。?/td> 787K
代理商: COP8SAC740N9
9.0 Interrupts
(Continued)
ample, if the Software Trap routine is located at 0310 Hex,
then the vector location 0yFE and -0yFF should contain the
data 03 and 10 Hex, respectively. When a Software Trap in-
terrupt occurs and the VIS instruction is executed, the pro-
gram jumps to the address specified in the vector table.
The interrupt sources in the vector table are listed in order of
rank, from highest to lowest priority. If two or more enabled
and pending interrupts are detected at the same time, the
one with the highest priority is serviced first. Upon return
from the interrupt service routine, the next highest-level
pending interrupt is serviced.
If the VIS instruction is executed, but no interrupts are en-
abled and pending, the lowest-priority interrupt vector is
used, and a jump is made to the corresponding address in
the vector table. This is an unusual occurrence, and may be
the result of an error. It can legitimately result from a change
in the enable bits or pending flags prior to the execution of
the VIS instruction, such as executing a single cycle instruc-
tion which clears an enable flag at the same time that the
pending flag is set. It can also result, however, from inadvert-
ent execution of the VIS command outside of the context of
an interrupt.
The default VIS interrupt vector can be useful for applica-
tions in which time critical interrupts can occur during the
servicing of another interrupt. Rather than restoring the pro-
gram context (A, B, X, etc.) and executing the RETI instruc-
tion, an interrupt service routine can be terminated by return-
ing to the VIS instruction. In this case, interrupts will be
serviced in turn until no further interrupts are pending and
the default VIS routine is started. After testing the GIE bit to
ensure that execution is not erroneous, the routine should
restore the program context and execute the RETI to return
to the interrupted program.
This technique can save up to fifty instruction cycles (t
), or
more, (50 μs at 10 MHz oscillator) of latency for pending in-
terrupts with a penalty of fewer than ten instruction cycles if
no further interrupts are pending.
To ensure reliable operation, the user should always use the
VIS instruction to determine the source of an interrupt. Al-
though it is possible to poll the pending bits to detect the
source of an interrupt, this practice is not recommended. The
use of polling allows the standard arbitration ranking to be al-
tered, but the reliability of the interrupt system is compro-
mised. The polling routine must individually test the enable
and pending bits of each maskable interrupt. If a Software
Trap interrupt should occur, it will be serviced last, even
though it should have the highest priority. Under certain con-
ditions, a Software Trap could be triggered but not serviced,
resulting in an inadvertent “l(fā)ocking out” of all maskable inter-
rupts by the Software Trap pending flag. Problems such as
this can be avoided by using VIS instruction.
TABLE 5. Interrupt Vector Table
Arbitration
Ranking
Vector
(Note 20)
Address
(Hi-Low Byte)
0yFE–0yFF
0yFC–0yFD
0yFA–0yFB
0yF8–0yF9
0yF6–0yF7
0yF4–0yF5
0yF2–0yF3
0yF0–0yF1
0yEE–0yEF
0yEC–0yED
0yEA–0yEB
0yE8–0yE9
0yE6–0yE7
0yE4–0yE5
0yE2–0yE3
0yE0–0yE1
Source
Description
(1) Highest
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16) Lowest
Software
Reserved
External
Timer T0
Timer T1
Timer T1
MICROWIRE/PLUS
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Port L/Wakeup
Default
INTR Instruction
Future
G0
Underflow
T1A/Underflow
T1B
BUSY Low
Future
Future
Future
Future
Future
Future
Future
Port L Edge
VIS Instruction
Execution without any interrupts
Note 20:
y is a variable which represents the VIS block. VIS and the vector table must be located in the same 256-byte block except if VIS is located at the last ad-
dress of a block. In this case, the table must be in the next block.
www.national.com
29
相關(guān)PDF資料
PDF描述
COP8SAC740Q3 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
COP8SAA716M8 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
COP8SAA716M9 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
COP8SAA716N8 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
COP8SAC744V7 8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
COP8SAC740Q3 功能描述:IC MCU EPROM 8 BIT 4K 40-DIP RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:COP8™ 8SA 其它有關(guān)文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標(biāo)準(zhǔn)包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C,IrDA,LIN,SPI,UART/USART 外圍設(shè)備:DMA,PDR,POR,PVD,PWM,溫度傳感器,WDT 輸入/輸出數(shù):26 程序存儲(chǔ)器容量:64KB(64K x 8) 程序存儲(chǔ)器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN,36-VFQFPN 包裝:托盤 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名稱:497-9032STM32F101T8U6-ND
COP8SAC740Q9 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller
COP8SAC744J3 功能描述:IC MCU EPROM 8 BIT 4K 44-PLCC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:COP8™ 8SA 其它有關(guān)文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標(biāo)準(zhǔn)包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C,IrDA,LIN,SPI,UART/USART 外圍設(shè)備:DMA,PDR,POR,PVD,PWM,溫度傳感器,WDT 輸入/輸出數(shù):26 程序存儲(chǔ)器容量:64KB(64K x 8) 程序存儲(chǔ)器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN,36-VFQFPN 包裝:托盤 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名稱:497-9032STM32F101T8U6-ND
COP8SAC744J9 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller
COP8SAC744V7 制造商:NSC 制造商全稱:National Semiconductor 功能描述:8-Bit CMOS ROM Based and One-Time Programmable OTP Microcontroller with 1k to 4k Memory, Power On Reset, and Very Small Packaging