GNU ARM汇编--(六)s3c2440的时钟控制

divN_UPLL = 0

UPLL是48M

HdivN = 01

PdivN = 1

FCLK : HCLK : PCLK = 1:2:4

datasheet读懂了,写出汇编就很容易了,添加了时钟设置的流水灯如下:

[cpp]view plaincopy

1. .equGPBCON,0x56000010
2. .equGPBDAT,0x56000014
4. .equGPB5_out,(1<(5*2))
5. .equGPB6_out,(1<(6*2))
6. .equGPB7_out,(1<(7*2))
7. .equGPB8_out,(1<(8*2))
9. .equGPBVALUE,(GPB5_out|GPB6_out|GPB7_out|GPB8_out)
11. .equLOCKTIME,0x4c000000
12. .equMPLLCON,0x4c000004
13. .equUPLLCON,0x4c000008
14. .equM_Mdiv,92
15. .equM_Pdiv,1
16. .equM_Sdiv,1
17. .equU_Mdiv,56
18. .equU_Pdiv,2
19. .equU_Sdiv,2
21. .equCLKdivN,0x4c000014
22. .equdivN_UPLL,0
23. .equHdivN,1
24. .equPdivN,1@FCLK:HCLK:PCLK=1:2:4
27. .global_main
28. _main:
30. ldrr0,=GPBCON
32. ldrr1,=0x15400
33. strr1,[r0]
35. @blclock_setup
37. ldrr2,=GPBDAT
39. ldrr1,=0x1c0
40. strr1,[r2]
41. bldelay
42. ledloop:
44. ldrr1,=0x1c0
45. strr1,[r2]
46. bldelay
48. ldrr1,=0x1a0
49. strr1,[r2]
50. bldelay
52. ldrr1,=0x160
53. strr1,[r2]
54. bldelay
56. ldrr1,=0x0e0
57. strr1,[r2]
58. bldelay
61. bledloop
63. clock_setup:
65. ldrr0,=LOCKTIME
66. ldrr1,=0xffffffff
67. strr1,[r0]
69. ldrr0,=CLKdivN
70. ldrr1,=(divN_UPLL<3)|(HdivN<1)|(PdivN<0)
71. strr1,[r0]
73. ldrr0,=UPLLCON
74. ldrr1,=(U_Mdiv<12)|(U_Pdiv<4)|(U_Sdiv<0)@Fin=12MUPLL=48M
75. strr1,[r0]
76. nop
77. nop
78. nop
79. nop
80. nop
81. nop
82. nop
83. ldrr0,=MPLLCON
84. ldrr1,=(M_Mdiv<12)|(M_Pdiv<4)|(M_Sdiv<0)@Fin=12MFCLK=400M
85. strr1,[r0]
89. movpc,lr
91. delay:
92. @ldrr3,=0xffffffff
93. ldrr3,=0xfffff
95. delay1:
96. subr3,r3,#1
98. cmpr3,#0x0
100. bnedelay1
102. movpc,lr