这两天玩了一下stm32f042的can,但是折腾了2个晚上,还是没有进展。我知道stm32f042F6P6 ssop20封装的pin17,pin18默认是PA9,PA10的功能,如果想使用PA11和PA12,需要进行端口映射。这样的话,我直接就用了下面的代码,进行端口映射,. D( y+ a) b8 ^4 c: C
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- SYSCFG_MemoryRemapConfig(SYSCFG_CFGR1_PA11_PA12_RMP);
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结果Can总线一直没有波形出来。使用回环模式调试,总线上一直没有波形。' S& _% p$ x- m& `
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由于CAN的PA11和PA12和串口1的PA9和PA10是复用的,没有第一时间使用串口进行调试。今天晚上下班将usart2飞线飞出来了。使能断言后,发现下面的断言错误。, Z' D: v. w K+ _5 k M% M: m
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- DEBUG [D] main:94 hello armwind
: o2 n) O+ G! _ S) C v8 } - DEBUG [D] assert_failed:94<div> …/Lib/STM32F0xx_StdPeriph_Driver/src/stm32f0xx_syscfg.c,line:119</div>
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7 a0 z$ X v5 R* {9 O/ G, E6 ~查看源码发现,断言表明,这个方法只能映射系统mem.
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- void SYSCFG_MemoryRemapConfig(uint32_t SYSCFG_MemoryRemap); {" B+ h- G' _, l4 Q& \9 S1 \7 M
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- uint32_t tmpctrl = 0;, `7 V' a; u6 f- u/ f8 @" X
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- /* Check the parameter */" a: l1 j) d9 O" G$ u4 H$ x7 S0 f
- assert_param(IS_SYSCFG_MEMORY_REMAP(SYSCFG_MemoryRemap));
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- /* Get CFGR1 register value *// a4 l0 E+ |+ y' Q% J& [
- tmpctrl = SYSCFG->CFGR1;3 S, W- @, Z0 e. @7 k+ f/ C
4 r/ e% Y# v4 r) |+ S, g- /* Clear MEM_MODE bits */
* q9 I2 V' H, }4 E8 M' c' Y) s - tmpctrl &= (uint32_t) (~SYSCFG_CFGR1_MEM_MODE);% y. r5 H: E% @! c9 x
% E/ L$ r9 q/ q9 `5 I; ^- /* Set the new MEM_MODE bits value */% m; b+ U' K8 q$ `
- tmpctrl |= (uint32_t) SYSCFG_MemoryRemap;# R5 k- L0 u* ?) w8 |
/ ^: o7 o" l2 o9 R9 ]0 R- /* Set CFGR1 register with the new memory remap configuration */+ U4 t' X8 D- Q1 E% t! \1 H( d
- SYSCFG->CFGR1 = tmpctrl;
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+ t1 ^7 V3 `/ J, m& M9 z- //宏定义很明显/ P9 X: T# K* u# L- @1 F9 v. s
- #define IS_SYSCFG_MEMORY_REMAP(REMAP) (((REMAP) == SYSCFG_MemoryRemap_Flash) || \ Y7 Y7 i6 p( V4 n
- ((REMAP) == SYSCFG_MemoryRemap_SystemMemory) || \, e( x$ B; l7 y( }) R2 O* v y
- ((REMAP) == SYSCFG_MemoryRemap_SRAM))
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所以使用下面代码即可map成功, G- c! W1 M( C5 \" _
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- //不要覆盖掉系统原始的配置
6 y! ~: u3 x8 S9 w5 j2 l4 V - SYSCFG->CFGR1 = SYSCFG->CFGR1 | SYSCFG_CFGR1_PA11_PA12_RMP;
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完整的Can初始化代码
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K2 a* o/ i' W3 Z7 t- void can_init(void)
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% Q1 b0 \ q! ]# T - GPIO_InitTypeDef GPIO_InitStructure;1 A2 W# F. X' g/ @
- NVIC_InitTypeDef NVIC_InitStructure;( O3 i) ~4 _2 F/ J4 ~
- CAN_InitTypeDef CAN_InitStructure;, E. F* G4 f1 ^
- CAN_FilterInitTypeDef CAN_FilterInitStructure;
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2 L7 r0 _4 C- @! ~4 ?/ x- RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
) ^" x2 D) k& N - SYSCFG->CFGR1 = SYSCFG->CFGR1 | SYSCFG_CFGR1_PA11_PA12_RMP;5 N! |9 w3 ?+ w3 [
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- /* Enable GPIO clock */
Q" n$ H8 \8 l7 a - RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);; \8 Z( f; y g! a1 i
- /* Connect CAN pins to AF7 */
+ p& a5 I. y/ h; l! W - /* CAN GPIOs configuration **************************************************/
y; A0 y" r% p. U - GPIO_PinAFConfig(GPIOA, GPIO_PinSource11, GPIO_AF_4);
5 @6 Y' X- T0 \ b# d r" Y7 N - GPIO_PinAFConfig(GPIOA, GPIO_PinSource12, GPIO_AF_4);$ t. y# S8 G: S/ F! i$ m
% B. T. H a- B: S- /* Configure CAN RX and TX pins */
$ V+ Y, ?7 G, f& e+ V# S - GPIO_InitStructure.GPIO_Pin = GPIO_PinSource11 | GPIO_PinSource12;
0 L# c# q: J7 M7 h - GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;; [9 Z. n4 l0 w- q. U
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
6 Q& N9 h0 ^- Y: g! N - GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;' `' s) J# l8 O1 `
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;3 @ E/ w+ J: e3 o/ R
- GPIO_Init(GPIOA, &GPIO_InitStructure);
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5 `9 I) P# T$ f E& w* m- /* NVIC configuration *******************************************************/8 X5 \, A5 i+ \# f3 q: U& v
- NVIC_InitStructure.NVIC_IRQChannel = CEC_CAN_IRQn;1 a6 g: _- K7 k/ b: Y
- NVIC_InitStructure.NVIC_IRQChannelPriority = 0x0;+ d! ~- i. `$ |/ |& N
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
3 j! Q* I8 i C! U - NVIC_Init(&NVIC_InitStructure); t1 m" ~; C3 B
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- /* CAN configuration ********************************************************// A2 t5 T5 }0 P
- /* Enable CAN clock */
1 }. l4 |7 P0 a! f1 ^ - RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN, ENABLE);/ f- o6 k* ~" k! P
# i( k7 [" |5 o1 o4 j1 g- /* CAN register init */) ]& ]* _, F# o: Z
- CAN_DeInit(CAN);
% p' [ O7 L1 Z9 o3 H - CAN_StructInit(&CAN_InitStructure);
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- /* CAN cell init */! R. s$ W4 t% u6 @
- CAN_InitStructure.CAN_TTCM = DISABLE;
! f7 N8 I1 u( M- U, p0 M( { - CAN_InitStructure.CAN_ABOM = DISABLE;# W: p/ O9 G2 I3 h" z2 E( B
- CAN_InitStructure.CAN_AWUM = DISABLE;5 w* R& b( D* X; g( I+ s
- CAN_InitStructure.CAN_NART = DISABLE;, |# ]7 u7 B9 X
- CAN_InitStructure.CAN_RFLM = DISABLE;
0 a2 U( ]4 K& @% L# l7 m( c - CAN_InitStructure.CAN_TXFP = DISABLE;
# x) W4 B& j% M4 D: S! S, @ - CAN_InitStructure.CAN_Mode = CAN_Mode_Normal;
+ c2 Q6 ]0 N4 D# W* d0 m - //CAN_InitStructure.CAN_Mode = CAN_Mode_LoopBack;
% M/ }: T( Q7 o6 q% \7 ~4 _ - CAN_InitStructure.CAN_SJW = CAN_SJW_1tq;
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- //200k的配置0 ^( J+ j6 M; t; T1 P
- //48M/12/(CAN_SJW_1tq + CAN_BS1_4tq+CAN_BS2_5tq) == 200k: f0 O, z% w& t2 o' i4 _2 w4 Y# ^$ B
- /* CAN Baudrate = 1MBps (CAN clocked at 36 MHz) */
& e( b% q4 i0 x4 R+ H+ A; Y - CAN_InitStructure.CAN_BS1 = CAN_BS1_4tq;# L4 z: U- T0 i! s
- CAN_InitStructure.CAN_BS2 = CAN_BS2_5tq;
5 F: ^1 W5 p4 C4 W* I$ I4 v - CAN_InitStructure.CAN_Prescaler = 12;
! E; N( H( }# Y: O - CAN_Init(CAN, &CAN_InitStructure);
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- /* CAN filter init */* C; b6 d5 _& V, O( `, i3 h
- CAN_FilterInitStructure.CAN_FilterNumber = 1;& b! s# \; L v4 V. ^
- CAN_FilterInitStructure.CAN_FilterMode = CAN_FilterMode_IdMask;* q0 [9 C6 A6 X' t1 B' O
- CAN_FilterInitStructure.CAN_FilterScale = CAN_FilterScale_32bit;. x1 I2 Z# h4 L, s0 u: g
- CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;. t Q4 c6 H; x% O9 N7 d
- CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;
' X$ h/ r. W- r9 C - CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;
7 |2 y9 ~9 e# t0 d' p - CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;2 j2 h& n* b) f x# Q+ l
- CAN_FilterInitStructure.CAN_FilterFIFOAssignment = 0;/ Q$ n' {" o( P
- CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;/ r4 `4 S/ `" E# m: @3 p
- CAN_FilterInit(&CAN_FilterInitStructure);
2 s9 T0 K& i: ]* G0 O6 w - /* Transmit Structure preparation */2 f n" `1 B; l8 O/ c/ L
( Z' ]4 Y* U$ P, X3 u& r- /* Enable FIFO 0 message pending Interrupt */
4 ], D* z2 G. e W/ s/ l. Y - CAN_ITConfig(CAN, CAN_IT_FMP0, ENABLE);
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