中断是单片机中最重要的一个功能了,通过中断可以提高程序的运行效率,可以是单片机及时的响应各种外设的请求。STM32系列单片机的中断主要由嵌套向量中断控制器来管理。
# v. S; a5 j( T! i+ L2 z( M+ m
/ j) J- }/ o$ y1 b$ d3 a0 d- g 嵌套向量中断控制器特性如下:/ Q* R6 ~, F% F; F) d
68个可屏蔽中断通道(不包含16个Cortex™-M3的中断线);
3 `1 t. I; F8 Y8 z2 S, X+ \16个可编程的优先等级(使用了4位中断优先级);$ v9 ]& |" h8 O9 A0 h
低延迟的异常和中断处理;. C A" O# ?- v0 I k( K
电源管理控制;* j, J0 G( d' J' u# r4 e
系统控制寄存器的实现;# p+ ~; J v5 x
嵌套向量中断控制器( NVIC ) 和处理器核的接口紧密相连,可以实现低延迟的中断处理和高效地
1 T; h3 P+ h' a+ F c! Y' d# z处理晚到的中断。 ^5 d- f# G' v5 ]
. q$ m! a! ?3 ~* p) z
外部中断/事件控制器由19个能产生事件/中断请求的边沿检测器。每个输入线可以独立地配置输入类型(脉冲或挂起)和对应的触发事件(上升沿或下降沿或者双边沿都触发)。每个输入线都可以独立地被屏
. Z( X, t L- m% j; c蔽。挂起寄存器保持着状态线的中断请求。
1 v6 b1 [$ R4 ^' o1 ]# {, K* O5 [+ L+ X
EXTI控制器的主要特性如下:5 {7 O# {- r9 L+ W9 W) u
$ n6 B0 d* a4 Z每个中断/事件都有独立的触发和屏蔽) z: w: ^, b' v8 j! o
每个中断线都有专用的状态位6 v# Y; H7 A# [/ h/ m$ G8 ?; }
支持多达20个软件的中断/事件请求
/ c4 O. O* @0 Y4 a. ^+ @: d0 j检测脉冲宽度低于APB2时钟宽度的外部信号。参见数据手册中电气特性部分的相关参数。
8 W% H$ R3 W0 i! n7 x
" u+ N# {4 X# C' q+ J9 L! P8 J
% i0 L% p: D# R+ k7 j( v中断控制框图如下:# Y% M F# E" D# L3 @/ I# c) C
, l- P2 D% n" C3 e8 l. p- w
' }' {2 o5 h8 N+ H
3 f- c; G% T& D6 `
下面用按键口作为中断检测口,来演示一下中断的使用方法。
$ N: @8 U' b2 a" p/ z$ \
3 b( S! {' D$ D/ c* s! l8 \0 L' A- //KEY0 PC1 KEY1 PC13 WK_UP PA0
' d* f& ?: ]7 n) r
7 u) E/ t' I6 j1 c- void KEY_Init(void)' i) `2 ?$ ~& h
- {/ p' j5 b \- L! i. j+ w
- GPIO_InitTypeDef GPIO_InitStructure;
3 ~- R' d& E2 h' u7 c - RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOC, ENABLE);( A& g* o2 [0 A4 w0 h
- & T$ Y0 l: _ R' X5 W% ?! u, {1 k& t
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_13;" w3 m4 Y7 ~9 l$ l y1 o/ P
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入0 w- L. n3 W& p- t+ o9 u2 `+ }
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;5 Q7 S- ^, V( J% @$ A/ l m9 U
- GPIO_Init(GPIOC, &GPIO_InitStructure);
5 g2 m* G, U$ n- ]
' ~) v$ D; A9 i- f5 N+ |; ]- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
8 x: ~) d' ~+ i) H2 L - GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //下拉输入
t1 E: B' Y4 E7 j - GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
3 Y! j0 Z2 G- W* }( U' n - GPIO_Init(GPIOA, &GPIO_InitStructure);
0 |. I/ Q4 O3 F' ~5 D, w - }
复制代码 2 y! p. z5 s# ]" M# {) m
首先初始化按键所使用的IO口,这里使用了三个按键,其中一个按键默认为低电平,按键按下后为高电平。其余两个按键默认是高电平,按下按键后为低电平。 下面开始初始化中断。# E. r2 ?; L6 J( F0 B
3 e/ m6 s2 { R7 T6 v1 h# r- //KEY0 PC1 KEY1 PC13 WK_UP PA05 G1 |. X: Z# W/ }- x) h& O
- void EXTIx_Init(void)
: `1 E* ~. k+ f/ {4 e1 k - {
' H- q. R* {- U C - EXTI_InitTypeDef EXTI_InitStructure;
8 A( h+ z+ c9 X* m1 V6 T - NVIC_InitTypeDef NVIC_InitStructure;# W8 }$ m5 f5 m8 B3 U
: W4 H3 ~# p; V- // 1、初始化IO: [9 G6 G( {0 `' m5 o+ y8 t& Z, y
- KEY_Init(); //按键端口初始化
# F. b8 X5 U1 j1 S T" |1 n - // 2、开启AFIO时钟
7 l3 ~, A, {3 b# `( o1 \ - RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); //使能复用功能时钟
# ~# q9 {9 y* t% k" C+ `1 U' E; ?; P - // 3、设置IO口与中断线的映射关系9 Q* f. P" w8 _) s
- GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0); //PA04 o' V: ^$ ?8 B5 p; g9 K
- // 4、初始化线上中断,设置触发条件
( ]* N) ]/ M6 g6 ^& j9 M- e } - EXTI_InitStructure.EXTI_Line = EXTI_Line0; //WK_UP 上升沿
3 r- ]1 Z8 O9 p - EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;# M# y+ J% I1 A1 ~0 v V3 t
- EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;2 S4 F& N# a0 J+ `- k
- EXTI_InitStructure.EXTI_LineCmd = ENABLE;; u+ m h$ r1 F% h
- EXTI_Init(&EXTI_InitStructure);8 E3 h( x8 Y$ Z. B) d& O
- - ]9 k% U# }! X4 \% v- s" c) M
- GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource1); //PC1
$ S5 ~+ J- N7 t3 C: d& I/ C
6 O; r3 @ l3 z A: R, E. k0 f- EXTI_InitStructure.EXTI_Line = EXTI_Line1; //KEY0 下降沿8 w- K+ \: h& Y' ]3 J# [4 A6 [6 j5 f
- EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
; @2 m. }6 J! w" h - EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;$ L N) H o7 _7 j
- EXTI_InitStructure.EXTI_LineCmd = ENABLE;
D* l2 u- O$ M, J9 { - EXTI_Init(&EXTI_InitStructure);
5 ]1 D& F3 |* A4 r* h# n
' ~$ T( I( i3 P2 b0 J- GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource13);//PC13
- F0 p! }" L( ^8 s - % J* {( l) g" R) u; g3 Z2 o
- EXTI_InitStructure.EXTI_Line = EXTI_Line13; //KEY1 上升沿
z! s$ Y* E& I* _+ l; z7 @, i - EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
. |. P( \. ^4 T% S0 q - EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
: Y1 E9 A) }8 N' I. C7 n3 Q - EXTI_InitStructure.EXTI_LineCmd = ENABLE;. t1 w6 _$ K4 I: p. E5 ~
- EXTI_Init(&EXTI_InitStructure);$ I( O" m, f. ]/ J* j
- // 5、配置中断分组,并使能中断
+ [0 I( W+ L8 b' y% J - NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;4 @' ]$ I% G: R% U9 x; j
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
. H, ? \1 H3 J5 N3 u - NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;" F2 i7 g$ i& y
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
6 U# @/ {) Z# u - NVIC_Init(&NVIC_InitStructure);! P8 i. C9 o$ ^/ f5 |4 v b# w8 l2 U
9 b9 T, {, F% ]6 u. |, i. U- NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;6 f3 e* ~2 z R1 l1 h% e3 x
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;1 F" k1 c" ^4 ?- \; z4 ?
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;) e/ U) i* i) d( C! C- v
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;7 @- G: K( S; e$ ]8 r7 y
- NVIC_Init(&NVIC_InitStructure);* S. k j; ]$ m$ a0 e2 {8 e" e' G
9 e- U- y1 e+ }- NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;
' n& { ^9 d0 c& h3 c3 M9 a - NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;& d3 w: g$ Q5 @4 J0 F
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;8 c+ W) E* ~! s, g& R) a2 l5 E
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
2 p) f, i! s% W5 T9 f4 l$ S# a4 }; L - NVIC_Init(&NVIC_InitStructure);
9 t+ j5 g& ?8 M- t5 E S - }' K( F/ f# q9 K
- % M2 F0 u4 k+ U- Y( A8 J4 y; f5 ?
- void EXTI0_IRQHandler(void)- d! z- K" `1 }- B3 @
- {+ s6 x: f4 e3 u i' e
- if(EXTI_GetITStatus(EXTI_Line0) != RESET)
2 u! Z' c" V) J/ w& g, O - {( ~8 w' ]- S0 h$ S7 _
- delay_ms(10);. U0 L0 {9 T& Z) J. n
- if(WK_UP == 1)
; j3 q! G' b/ v& Q - {
. x" M' w; T& b - LED0 = !LED0;
" n6 p+ A- t! @ - LED1 = !LED1;- t1 ]% J" I2 ^; r
- }* x- l; _" T& e+ S: q/ z$ S8 ~& S; Q
- EXTI_ClearITPendingBit(EXTI_Line0);/ m: s8 y1 I3 c. `* ?8 B+ E$ T
- }) x/ g- Y5 [9 o# F ]! Z
- }
z2 W$ h: B: Z - void EXTI1_IRQHandler(void)
- T! |) G/ e* i- c: E0 H% l - {: h$ O/ n+ x# C8 r) b
- if(EXTI_GetITStatus(EXTI_Line1) != RESET)& x6 ]. G* Z% [9 g
- {3 i- B8 a$ E4 p* x( Y
- delay_ms(10);
" [8 k6 r1 ? \8 |7 i: C( o) |- \& e, @ - if(KEY0 == 1)
1 R$ e9 h( c* v+ b A3 F% @ - { |3 c6 [: v+ R' {
- LED0 = !LED0;) [, G$ @5 H: h3 M$ N( ` [# o8 r
- }
: z9 ]7 v/ v- J* |! _ - EXTI_ClearITPendingBit(EXTI_Line1);
Y" Z; _, O; H - }
+ ^" ~; Q8 c. \- h* ` - }5 ^, W, t) {! r4 @
- void EXTI15_10_IRQHandler(void)
1 Q6 F3 e' ^0 t. m7 E7 a5 W - {
9 T5 v# P8 @( P* G' w' A - if(EXTI_GetITStatus(EXTI_Line13) != RESET)
; C2 x. z7 \5 n( N - {
/ s( S3 }) Y E8 d0 A! a4 ? - delay_ms(10);
3 y& a, @& S1 p# l - if(KEY1 == 1)
+ `' ] p. T+ q/ i; \' Q$ _# p - {
6 K# P2 m# R% h- R1 r - LED1 = !LED1;& \. t$ `) |0 S* Q
- }; C. r/ L U& }4 {# l) N, e: _
- EXTI_ClearITPendingBit(EXTI_Line13);$ `& z6 K- w: C
- }2 L/ C: ?/ f9 P. i
- ) F# b5 W6 }) q! U. R
- }
复制代码 1 o) n" W! O6 l6 q( A; }4 ]
初始化中断时需要设置每个IO口对应的中断线,中断线对应关系如下图:
9 w/ u% k6 N; C$ z7 ]9 ]0 J; z* @5 s7 M
8 p' h0 q* ?, B; B5 S8 ~
1 k% \! W+ r" o 通过上图可以看出所有的P0口对应的都是中断线0,所有的P1口对应的都是中断线1,依次类推。这里使用的三个按键分别是PC1、PC13、PA0,也就是对应的中断线为中断线1、中断线13、中断线0。& A1 g( ^8 H+ h* _" s/ F- [
* g& D+ G+ j4 U3 h, \1 d& r4 g5 b
中断线设置完成之后,还需要设置中断分组,也就是设置中断的优先级,当中断同时触发的时候,优先级越高的中断优先处理。# k: r6 C, d; y# Z, r+ b( [# P
8 i6 m! B# \, m1 t+ o% D
中断线设置好之后,还需要提供中断入口函数,因为中断触发后,系统就会自动跳转到中断入口函数中,执行中断函数的代码。每个中断入口的函数名称都是固定的,不能自己定义。中断函数的入口名称可以在startup_stm32f10x_hs.s文件中查看。
0 J6 ]" P( C1 t, n2 y) w7 M n$ K" Z! V) v
- ; External Interrupts. r- h3 K, ?1 {
- DCD WWDG_IRQHandler ; Window Watchdog
8 V1 u' Y! S0 } - DCD PVD_IRQHandler ; PVD through EXTI Line detect! h! F# S/ p7 X0 k; r) g( `2 M
- DCD TAMPER_IRQHandler ; Tamper
. y9 b f! W: N - DCD RTC_IRQHandler ; RTC; y" v: n7 [ @; T
- DCD FLASH_IRQHandler ; Flash) }" X1 p4 X/ B7 |& v" r
- DCD RCC_IRQHandler ; RCC
- e% t" I) w# w, c - DCD EXTI0_IRQHandler ; EXTI Line 0
' p# ?* i, m" Y1 r" k- Y% R' N* C q - DCD EXTI1_IRQHandler ; EXTI Line 1
7 A2 b7 G* L! `; Q* o4 `# [" _ - DCD EXTI2_IRQHandler ; EXTI Line 2
" I i$ J6 @; W, s" [( b - DCD EXTI3_IRQHandler ; EXTI Line 3" ^# P$ i& |# H7 ]! _5 u p
- DCD EXTI4_IRQHandler ; EXTI Line 4. ^" D8 l( h7 ~0 q6 F1 ?8 R+ \
- DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 14 O0 }# ^/ I* N1 _# o/ K
- DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2
) d5 q, n* x+ k E0 y/ a - DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 32 b9 R8 i- x: g& }$ {) P- {# x, J
- DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 44 Q t: a, V) F! b3 J
- DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5
7 r4 J$ p# d: c' M3 l/ V1 ^. k - DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6) C0 T. R+ @4 H3 y
- DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7! [( f& m7 l6 V! o# z) M/ k
- DCD ADC1_2_IRQHandler ; ADC1 & ADC2
; w1 r- Y2 l. E - DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX2 X3 h" `+ k2 V* z3 A# t
- DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0' @; r' n! _ B: c6 Q/ V
- DCD CAN1_RX1_IRQHandler ; CAN1 RX1( B% g. d# J2 U3 E3 b
- DCD CAN1_SCE_IRQHandler ; CAN1 SCE) J/ v, o9 M+ z4 }6 Y: Z" H
- DCD EXTI9_5_IRQHandler ; EXTI Line 9..50 v A1 p+ Y' h6 m% A
- DCD TIM1_BRK_IRQHandler ; TIM1 Break0 i# Z0 T# X( H; }/ R
- DCD TIM1_UP_IRQHandler ; TIM1 Update0 T; p" Y S0 E8 z" V
- DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation
8 z$ {/ H8 F! R* O8 B# h - DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare) T' t- V# P* u8 Q5 m8 C1 h
- DCD TIM2_IRQHandler ; TIM2* S: q+ \, M8 f' l
- DCD TIM3_IRQHandler ; TIM3& S. ~+ {6 C+ E5 c/ P
- DCD TIM4_IRQHandler ; TIM4
# A1 m( \5 ~1 Z; x9 }% e - DCD I2C1_EV_IRQHandler ; I2C1 Event) h+ N* H2 {3 k6 ~
- DCD I2C1_ER_IRQHandler ; I2C1 Error+ @1 c% d# o$ `
- DCD I2C2_EV_IRQHandler ; I2C2 Event
, t" r& @; u; p4 w: z: l - DCD I2C2_ER_IRQHandler ; I2C2 Error
0 h: U# `. j8 r+ {8 [4 j - DCD SPI1_IRQHandler ; SPI1
3 B; C" g4 r2 H% X! y; q6 W - DCD SPI2_IRQHandler ; SPI2
' d! ^! E8 j* x8 N. O8 A6 a - DCD USART1_IRQHandler ; USART1
7 F F4 T+ l3 n: p1 e" }, o - DCD USART2_IRQHandler ; USART2: t) G% r+ H) K$ K, O/ m( n
- DCD USART3_IRQHandler ; USART35 V. ?& C, t$ O) Y
- DCD EXTI15_10_IRQHandler ; EXTI Line 15..10: M, m$ W$ B- o; y' k, F
- DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line+ T; [& P5 I4 G+ H
- DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend+ ^2 i/ k6 D# q' n. U5 N5 I' K
- DCD TIM8_BRK_IRQHandler ; TIM8 Break; R$ g7 u; j e9 v) q4 r: y _
- DCD TIM8_UP_IRQHandler ; TIM8 Update
O& p/ f6 g2 g t; _$ `$ V6 a& h - DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation" e6 q* g! ~+ l, V( e, e1 u, c
- DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare+ ~8 x& e% ?. g: F! W* F- A( V
- DCD ADC3_IRQHandler ; ADC3
J! N5 ^( K0 D$ D - DCD FSMC_IRQHandler ; FSMC
- s, A3 |% f( a! v) X# O$ o - DCD SDIO_IRQHandler ; SDIO
- l1 j* v6 k3 P7 n& v0 T; I2 a7 d% w - DCD TIM5_IRQHandler ; TIM5
l$ |& N$ v5 r+ Z2 s H - DCD SPI3_IRQHandler ; SPI3
& F( x; X1 V! x! _ - DCD UART4_IRQHandler ; UART4
! r* i' s6 l5 ~: R9 b& b - DCD UART5_IRQHandler ; UART5
" a6 J; w" V/ Q, q" f8 Q& R - DCD TIM6_IRQHandler ; TIM6
5 Z$ e ^+ E0 ]$ a$ n - DCD TIM7_IRQHandler ; TIM7: Y8 B% W* Z, I, W, z$ c5 g" l; |
- DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1/ @/ ~7 s2 e4 H' U- U$ J5 [
- DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2* i. @7 f2 U3 `0 l6 L
- DCD DMA2_Channel3_IRQHandler ; DMA2 Channel36 K# c- t4 G" B9 D( t! K& e2 Q
- DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5
复制代码
2 d9 D) h( z- n3 N) t2 m这里的中断向量表中列出了所有中断函数入口名称。" U' [) E/ T# `. F
& b( T" C) |( p) D* U# M5 w- j2 ^当按键按下后,程序就会跳转到中断函数中去,在中断函数中通过LED灯来指示不同按键按下的效果。3 t; j# g) U: Q6 k- N
( {) p. d8 A- [7 s! ]/ I; Q' T* z" `
|