|
|
EDA365欢迎您登录!
您需要 登录 才可以下载或查看,没有帐号?注册
x
本帖最后由 Ele_insect 于 2022-9-26 16:04 编辑 1 L) r) |. B. E$ j3 z4 n
% D6 z, @/ O3 y) d9 D. w: G6 g
#include <msp430x14x.h>/ i: E; q9 @3 r; e
#include ( I5 A; K7 T9 u( h, c
#define uchar unsigned char
) U# { y5 _; I8 ]* [: k4 \5 `* D#define uint unsigned int" X+ f& w( m, a- P; r
#define CPU_F ((double) 8000000.0)//当前CPU主频
& n+ }. _* S- W8 {#define delay_us(x) __delay_cycles((long)(CPU_F*(double)x/1000000.0)); q9 I7 ^. m4 Y9 q1 L
#define delay_ms(x) __delay_cycles((long)(CPU_F*(double)x/1000.0)). W- M" p1 e6 `; s2 O6 l7 s
uint sintable[]={255,246,239,225,213,200,180,162,130,122,108,95,80,59,39,28,17,10,3,1,3,10,
* \' b4 S2 y6 H- ~( O) o17,28,39,59,80,95,108,122,130,162,180,200,213,225,239,246,255};
; Q5 W4 I2 s. @* G Quint t=0;
% g' c& b; T2 i" nvoid Init_clk()//时钟初始化
; \+ F5 [' q- S4 M, ^7 c9 [{
( \% ?) E. W3 t8 O8 r$ g uchar i;3 h4 m& v: N2 T2 B* m H* O( s" L1 g
BCSCTL1 &=~XT2OFF;//(置TX2=0)使TX2有效,默认是关闭的
3 E! S f5 k% ]7 D# ? do0 Z) p3 S9 E8 F+ k; i
{8 V7 E7 o0 Q7 Y. W" W
IFG1 &= ~OFIFG;//清振荡器失效标志7 R# C9 X0 d0 @, ?
for(i=0xff;i>0;i--);
( G& d O+ y( n, y/ x& e }while((IFG1 & OFIFG)!=0); //若振荡器失效标志有效
" N0 l. f" Q, E/ X! o BCSCTL2|=SELM_2+SELS+DIVS_2; //使MCLK=XT2=8M,SMCLK经过4分频,则SMCLK=2M
8 A; c4 X- G& c) J8 g4 t2 d- L z& K}
; \& h; n* P; g, \4 k0 vvoid main(void)% q2 P* P8 k9 H% Q# a
{ . e1 a8 V7 `4 s2 J
WDTCTL = WDTPW + WDTHOLD; 9 L, B% x, z3 c+ l* o
Init_clk(); //时钟初始化
& J; T I' H2 j; L+ C8 ` P4DIR |= 0x07; // P4.0 - P4.2 输出% l1 f( P7 i' w. v, i
P4SEL |= 0x07; // P4.0 - P4.2 第二功能(PWM输出)
* \- q! u; {6 z! b, P9 W0 l. Q7 O. T TBCTL = TBSSEL_2 + MC_1; // SMCLK,增计数模式
# ]! ?' W! I7 [ TBCCTL0 |=CCIE; //CCR0比较模式,打开中断
0 u5 \6 G& d; R1 U: S TBCCR0 = 255; //PWM周期 : _& X3 x! I) q7 p4 E
! H5 C2 n8 E5 a0 K+ l/ H TBCCTL1 = OUTMOD_7; //选择输出模式7,当TBR计数到0时,CCRx数据加载到TBCTLx中 7 n& Y+ O y: F' a% v7 k
TBCCTL2 = OUTMOD_7; 4 r$ A5 L+ o; l) Y
2 K/ ?; ?9 p/ Y7 |# ?' E9 B% Z TBCCR1 =sintable[t];6 A$ }8 _- {( u# F5 M! k9 \ ^( u% e
TBCCR2 = 128; //占空比128/255=50% + X2 q# Z+ b" P
while(1)
% ^2 J1 D- ^1 @+ _9 h1 ] T {
: |6 V& J: z* w5 O& e! L5 S _EINT();//打开总中断
9 h6 n4 a/ U! O( S }
9 R: G# g) e0 v# c; T6 T: p}
6 a3 F3 r" d6 v+ `. J" f& D#pragma vector=tiMERB0_VECTOR# T- b- ~" A& P3 [5 l" p
__interrupt void timerB()
9 D" i' b$ [3 I; C{. T- k; m3 ~% }: q. m3 s
t=(t+1)%39;
/ |4 y; b/ t! }7 t) h5 o TBCCR1=sintable[t];//将新的抽样值装入TBCCR1
4 v# A! F, B' O: X, P}8 h& f# q3 K' o8 c. p) w
- y1 y# B: ~/ G
' m# F5 X# E. D; X |
|