GNU ARM汇编--(九)s3c2440的PWM

1. sublr,lr,#4
2. stmfdsp!,{r0-r12,lr}
5. blirq_isr
6. ldmfdsp!,{r0-r12,pc}^
9. irq_isr:
11. ldrr2,=GPBDAT
12. ldrr1,=0x0e0
13. strr1,[r2]
16. ldrr0,=EINTPEND
17. ldrr1,=0xf0
18. strr1,[r0]
20. ldrr0,=SRCPND
21. ldrr1,=0x3ff@0b11111
22. strr1,[r0]
24. ldrr0,=SUBSRCPND
25. ldrr1,=0x3ff@0x1<13
26. strr1,[r0]
28. ldrr0,=INTPND
29. ldrr1,=0x3ff@0b11111
30. strr1,[r0]
32. movpc,lr
35. delay:
37. ldrr3,=0xffffff
39. delay1:
40. subr3,r3,#1
42. cmpr3,#0x0
44. bnedelay1
46. movpc,lr
49. clock_setup:
51. ldrr0,=LOCKTIME
52. ldrr1,=0xffffffff
53. strr1,[r0]
55. ldrr0,=CLKdivN
56. ldrr1,=(divN_UPLL<3)|(HdivN<1)|(PdivN<0)
57. strr1,[r0]
59. ldrr0,=UPLLCON
60. ldrr1,=(U_Mdiv<12)|(U_Pdiv<4)|(U_Sdiv<0)@Fin=12MUPLL=48M
61. strr1,[r0]
62. nop
63. nop
64. nop
65. nop
66. nop
67. nop
68. nop
69. ldrr0,=MPLLCON
70. ldrr1,=(M_Mdiv<12)|(M_Pdiv<4)|(M_Sdiv<0)@Fin=12MFCLK=400M
71. strr1,[r0]
75. movpc,lr
78. uart_init:
79. ldrr0,=GPHCON
80. ldrr1,=0x2aaaa@配置GPIO复用规则为串口
81. strr1,[r0]
83. ldrr0,=ULCON0
84. ldrr1,=(IR_MODE<6)|(Parity_Mode<3)|(Num_of_stop_bit<2)|(Word_length<0)@
85. strr1,[r0]
87. ldrr0,=UCON0
88. ldrr1,=(FCLK_Div<12)|(Clk_select<10)|(Tx_Int_Type<9)|(Rx_Int_Type<8)|(Rx_Timeout<7)|(Rx_Error_Stat_Int<6)|(Loopback_Mode<5)|(Break_Sig<4)|(Tx_Mode<2)|(Rx_Mode<0)
89. strr1,[r0]
91. ldrr0,=UFCON0
92. ldrr1,=(Tx_FIFO_Trig_Level<6)|(Rx_FIFO_Trig_Level<4)|(Tx_FIFO_Reset<2)|(Rx_FIFO_Reset<1)|(FIFO_Enable<0)@
93. strr1,[r0]
95. ldrr0,=UBRdiv0
96. ldrr1,=(UBRdiv<0)
97. strr1,[r0]
99. movpc,lr
101. Buzzer_Freq_Set:
103. //ldrr0,=GPBCON
104. //ldrr1,=0x15400@这个时候暂不配置GPB0为TOUT0，这时候只是配置GPB0为TOUT0
105. //strr1,[r0]
107. ldrr2,=GPBDAT
108. ldrr1,=0x1c1
109. strr1,[r2]
111. ldrr2,=GPBCON
112. ldrr1,[r2]
113. ldrr1,[r1]
114. //ldrr1,=0x15400
115. bicr1,r1,#0x3
116. orrr1,r1,#0x2
117. strr1,[r2]
119. ldrr2,=GPBDAT
120. ldrr1,=0x1a0
121. strr1,[r2]
123. ldrr1,=TCFG0
124. ldrr2,=(Prescaler0<0)
125. strr2,[r1]
127. ldrr1,=TCFG1
128. ldrr2,=(DMA_MODE<20)|(MUX0<0)
129. strr2,[r1]
131. //ldrr3,[r0]
132. //strr3,[r2]
136. //movr2,r0
138. ldrr1,=TCNTB0
139. //ldrr2,=200
140. strr0,[r1]
142. movr0,r0,LSR#2
144. ldrr1,=TCMPB0
145. //ldrr2,=50
146. strr0,[r1]
150. ldrr1,=TCON
151. ldrr2,=(DZ_eable<4)|(auto_reload<3)|(inverter<2)|(man_update<1)|(start<0)
152. strr2,[r1]
154. ldrr1,=TCON
155. ldrr2,=(DZ_eable<4)|(auto_reload<3)|(inverter<2)|(clear_man_update<1)|(start<0)
156. strr2,[r1]
158. ldrr2,=GPBDAT
159. ldrr1,=0x1a0
160. strr1,[r2]
162. movpc,lr
164. main:
166. ldrr1,=TCON
167. ldrr2,=(DZ_eable<4)|(auto_reload<3)|(inverter<2)|(man_update<1)|(stop<0)
168. strr2,[r1]
170. ldrlr,=loop
172. ldrpc,_pwm_uart_test
174. _pwm_uart_test:.wordpwm_uart_test
175. loop:
176. bloop@死循环
182. undefined_instruction:
183. nop
184. software_interrupt:
185. nop
186. prefetch_abort:
187. nop
188. data_abort:
189. nop
190. not_used:
191. nop
192. fiq:
193. nop
     

pwm_uart_test.c内容如下:

[cpp]view plaincopy

1. #include"pwm_uart_test.h"
2. externvoidBuzzer_Freq_Set(intfreq);
3. //externvoidBuzzer_Freq_Set(void);
4. charuart_GetByte(void)
5. {
6. while(!(rUTRSTAT0&0x1));//WaituntilTHRisempty.
7. returnRdURXH0();
8. }
11. voiduart_GetString(char*pt)
12. {
13. while(*pt)
14. uart_GetByte();
15. }
18. voiduart_SendByte(intdata)
19. {
21. if(data==)
22. {
23. while(!(rUTRSTAT0&0x2));
24. WrUTXH0();
25. }
26. while(!(rUTRSTAT0&0x2));//WaituntilTHRisempty.
27. WrUTXH0(data);
29. }
31. //====================================================================
32. voiduart_SendString(char*pt)
33. {
34. while(*pt)
35. uart_SendByte(*pt++);
36. }
39. voiduart_test(void)
40. {
42. charstr[20]="helloworld";
43. inta=97;
44. //while(1)
45. //uart_SendByte(a);
46. uart_SendString(str);
47. chars=uart_GetByte();
48. //if(s==a)
49. if(s==97)
50. rGPBDAT=0x1c0;
51. //uart_SendByte(a);
52. //uart_SendByte(97);
53. //uart_SendByte(a);
54. uart_SendByte((int)s);
55. uart_SendByte((int)s);
56. }
58. voidpwm_uart_test(void)
59. {
60. intfreq=10;
61. Buzzer_Freq_Set(freq);
62. //Buzzer_Freq_Set();
64. uart_SendString("start");
65. /*
66. inti;
67. for(i=0;i<1000;i++)
68. uart_SendString("wait");
69. while(1)
70. {
71. charkey=uart_GetByte();
72. uart_SendByte(key);
73. if(key==a||key==A)
74. {
75. if(freq<2000)//lci20000
76. freq+=10;
77. uart_SendByte(a);
78. Buzzer_Freq_Set(freq);
79. }
81. if(key==b||key==B)
82. {
83. if(freq>11)
84. freq-=10;
85. uart_SendByte(b);
86. Buzzer_Freq_Set(freq);
87. }
89. //uart_SendString(" Freq=%d",freq);
90. //if(key==ESC_KEY)
91. //{
92. //Buzzer_Stop();
93. //return;
94. //}
96. }
98. */
99. }

在这个例子中,既有汇编调用c,也有c调用汇编.可供以后参考.目前,串口输入还有些问题,还得继续调一下.串口遇到一个想不明白的问题,单单串口是正常的,但在打开PWM定时器后,串口就出问题了,打印只能出前面几个字符,这是个神马情况,有人知道的请帮我下,thks!

从代码中有这样的设定:

定时器的输入时钟为@定时器输入时钟周期 = PCLK/(prescaler + 1)/(divider value)
@clk = 100M/(249+1)/8=25k

TCNTB0设为200,而TCMPB0为50,则TOUT0输出占空比为25%的方波,方波的周期为200/clk=8ms

如果有示波器,倒可以验证一下这个结果.如果有对朋友觉得这个方波估计的不对,欢迎指出,谢谢！