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//---------------------------------------------------------- void Delay(uint32_t temp) //¼òµ¥µÄÑÓʱº¯Êý£¬ÓÃÓÚ°´¼üÏû¶¶ { for(; temp != 0; temp--); } " P& C9 ^( T5 D % r: L5 _- u# s; D' ~' `0 W //---------------------------------------------------------- //----------------------------------------------------------' z+ R- T% a+ Y3 p1 q) t' L unsigned long i; int main(void) { unsigned int j; /*!< At this stage the microcontroller clock setting is already configured, this is done through SystemInit() function which is called from startup" R& t6 v. V" i- u! ~9 \3 F file (startup_stm32f0xx.s) before to branch to application main. To reconfigure the default setting of SystemInit() function, refer to system_stm32f0xx.c file2 G3 [* _0 s) l$ t- N- q3 j *// u5 @' V. F$ f; V$ e& p! r& [ /* GPIOC Periph clock enable */ RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);) [- ]) T' z6 p: u) _; a+ h 9 r; H- {" v! T /* Configure PC8 and PC9 in output pushpull mode */0 K0 k' m4 |( ? GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;: P# R1 ^7 K. V4 @! D, { GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;6 E f1 z `: c* v) \ GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;; ~1 Z1 }7 {/ z( j8 U) l1 { GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;7 l/ u' d' f6 ]/ D# ^: q GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOC, &GPIO_InitStructure);+ v+ r; |( {9 i- X4 p# u% I k" [) Q# k6 q- k' R //----------------------------------------------------------( ?- n( H( [* a( X# j* _3 ~ ( b, t' s8 j7 A( ] \ //Ê×ÏȶÔkey½øÐгõʼ»¯£¬Ò²¾ÍÊÇÉèÖÃGPIO µÄģʽ5 ^" {& I* c: g& D0 q6 i/ j // GPIO_InitTypeDef GPIO_InitStructure; //µ÷ÓÃIO¶¨ÒåµÄ½á¹¹Ìå: r( P8 t, v- k1 c RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); //ʹÄÜ°´¼üIOµÄʱÖÓ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 ; //ÉèÖÃÁ¬½Ó°´¼üµÄIO¶Ë¿Ú GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN; //ÉèÖö˿ÚΪÊäÈëģʽ GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_3; //ÉèÖÃËÙ¶ÈΪµÚÈý¼¶ GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //ÉÏÀÊäÈë GPIO_Init(GPIOA, &GPIO_InitStructure); //°ÑÉèÖõIJÎÊýÓõ½½á¹¹Ìå 3 x S' a. _, C9 g( z ! R1 n7 q3 E& ^1 b0 h- l7 I: ] /* To achieve GPIO toggling maximum frequency, the following sequence is mandatory. 8 H- k2 L# D- r1 z$ P* P! ? You can monitor PC8 and PC9 on the scope to measure the output signal. If you need to fine tune this frequency, you can add more GPIO set/reset X) d: G& O2 }: d% o0 x cycles to minimize more the infinite loop timing. This code needs to be compiled with high speed optimization option. */$ ]1 r$ T' h h , u3 T9 t7 c. F# V( J2 } while (1)& r! e- w7 D: R! T, Q6 H" n { 1 G3 e) o; G# b if(GPIO_ReadInputDataBit(GPIOA,GPIO_Pin_0) == 0 ) # J4 V- m2 y4 P! n h { 1 M0 |/ X, f( _3 q /* Set PC8 and PC9 */ for(j=0;jBSRR |= (0x20BRR |= (0x400>>j); 2 y; B, N& f$ v) t' w% q9 J. L Delay(5000000); } ) ^) v" t/ z) X, H, [% ~ } else { + H; T* h' I" ]; ^' z /* Set PC9 */! l) t- Q9 u K GPIOC->BSRR |= 0x0200; Delay(1000000); 1 c- x2 D* z9 h ' }) T# X1 ?8 s: W& S0 ^- ?) T /* Reset PC9 */9 u) v8 b" Q |/ U) W" D # j$ S7 C2 i$ L" \& g0 b+ F GPIOC->BRR |= 0x0200; Delay(1000000); 1 p) S9 ?7 D% m0 e0 `! ^ ! J: H3 \4 y2 Z6 E }; }5 t6 J* `+ O( _: V% {2 L } |
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