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GNU ARM汇编--(七)s3c2440的串口控制

作者： 时间：2016-11-26 来源：网络 收藏
  • .global_main
  • _main:
  • ldrr0,=GPBCON
  • ldrr1,=0x15400
  • strr1,[r0]
  • ldrr2,=GPBDAT
  • blclock_setup
  • bluart_init
  • bldelay
  • ldrlr,=loop
  • @bluart_testdd
  • ldrpc,_uart_test
  • _uart_test:.worduart_test
  • loop:
  • bloop@死循环
  • ledloop:
  • ldrr1,=0x1c0
  • strr1,[r2]
  • bldelay
  • ldrr1,=0x1a0
  • strr1,[r2]
  • bldelay
  • ldrr1,=0x160
  • strr1,[r2]
  • bldelay
  • ldrr1,=0x0e0
  • strr1,[r2]
  • bldelay
  • bledloop
  • clock_setup:
  • ldrr0,=LOCKTIME
  • ldrr1,=0xffffffff
  • strr1,[r0]
  • ldrr0,=CLKDIVN
  • ldrr1,=(DIVN_UPLL<<3)|(HDIVN<<1)|(PDIVN<<0)
  • strr1,[r0]
  • ldrr0,=UPLLCON
  • ldrr1,=(U_MDIV<<12)|(U_PDIV<<4)|(U_SDIV<<0)@Fin=12MUPLL=48M
  • strr1,[r0]
  • nop
  • nop
  • nop
  • nop
  • nop
  • nop
  • nop
  • ldrr0,=MPLLCON
  • ldrr1,=(M_MDIV<<12)|(M_PDIV<<4)|(M_SDIV<<0)@Fin=12MFCLK=400M
  • strr1,[r0]
  • movpc,lr
  • uart_init:
  • ldrr0,=GPHCON
  • ldrr1,=0x2aaaa@配置GPIO复用规则为串口
  • strr1,[r0]
  • ldrr0,=ULCON0
  • ldrr1,=(IR_MODE<<6)|(Parity_Mode<<3)|(Num_of_stop_bit<<2)|(Word_length<<0)@
  • strr1,[r0]
  • ldrr0,=UCON0
  • 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)
  • strr1,[r0]
  • ldrr0,=UFCON0
  • ldrr1,=(Tx_FIFO_Trig_Level<<6)|(Rx_FIFO_Trig_Level<<4)|(Tx_FIFO_Reset<<2)|(Rx_FIFO_Reset<<1)|(FIFO_Enable<<0)@
  • strr1,[r0]
  • ldrr0,=UBRDIV0
  • ldrr1,=(UBRDIV<<0)
  • strr1,[r0]
  • movpc,lr
  • delay:
  • @ldrr3,=0x4ffffff
  • ldrr3,=0xfffff
  • delay1:
  • subr3,r3,#1
  • cmpr3,#0x0
  • bnedelay1
  • movpc,lr
    •

    UART的测试代码用C写的:

    本文引用地址： //m.amcfsurvey.com/article/201611/321724.htm

    uart_test.c:

    [cpp]view plaincopy
    1. #include"uart_test.h"
    3. charuart_GetByte(void)
    4. {
    5. while(!(rUTRSTAT0&0x1));//WaituntilTHRisempty.
    6. returnRdURXH0();
    7. }
    10. voiduart_GetString(char*pt)
    11. {
    12. while(*pt)
    13. uart_GetByte();
    14. }
    17. voiduart_SendByte(intdata)
    18. {
    20. if(data==)
    21. {
    22. while(!(rUTRSTAT0&0x2));
    23. WrUTXH0();
    24. }
    25. while(!(rUTRSTAT0&0x2));//WaituntilTHRisempty.
    26. WrUTXH0(data);
    28. }
    30. //====================================================================
    31. voiduart_SendString(char*pt)
    32. {
    33. while(*pt)
    34. uart_SendByte(*pt++);
    35. }
    38. voiduart_test(void)
    39. {
    41. charstr[20]="helloworld";
    42. inta=97;
    43. //while(1)
    44. //uart_SendByte(a);
    45. uart_SendString(str);
    46. chars=uart_GetByte();
    47. //if(s==a)
    48. if(s==97)
    49. rGPBDAT=0x1c0;
    50. //uart_SendByte(a);
    51. //uart_SendByte(97);
    52. //uart_SendByte(a);
    53. uart_SendByte((int)s);
    54. uart_SendByte((int)s);
    55. }
    uart_test.h:

    [cpp]view plaincopy
    1. //#defineWrUTXH0(ch)(*(volatileunsignedchar*)0x50000023)=(unsignedchar)(ch)
    2. #defineWrUTXH0(ch)(*(volatileunsignedchar*)0x50000020)=(unsignedchar)(ch)
    3. #defineRdURXH0()(*(volatileunsignedchar*)0x50000024)
    4. #definerUTRSTAT0(*(volatileunsigned*)0x50000010)//UART0Tx/Rxstatus
    6. #definerGPBDAT(*(volatileunsigned*)0x56000014)


    到此,使用串口的轮循模式,可以实现串口的正常收发功能了～～

    中断模式还没写,这个等到后面全面研究uboot的时候再回头看,uboot用哪种模式,应该就说明那种方式好,到时侯再实现吧
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    关键词：ARM汇编s3c2440串口控

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