1 | // I2C initialization
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2 | void I2CA_Init(void)
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3 | {
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4 | // Initialize I2C
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5 | //0101111(1) last 1 represents part of slave address but also a Read //command
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6 | I2caRegs.I2CSAR = 0x005F; // Slave address
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7 |
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8 | I2caRegs.I2CPSC.all = 9; // Prescaler - need 7-12 Mhz on module clk
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9 |
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10 | I2caRegs.I2CCLKL = 10; // NOTE: must be non zero
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11 | I2caRegs.I2CCLKH = 5; // NOTE: must be non zero
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12 | I2caRegs.I2CIER.all = 0x24; // Enable SCD & ARDY interrupts
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13 |
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14 | I2caRegs.I2CMDR.all = 0x0020; // Take I2C out of reset
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15 | // Stop I2C when suspended
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16 |
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17 | I2caRegs.I2CFFTX.all = 0x6000; // Enable FIFO mode and TXFIFO
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18 | I2caRegs.I2CFFRX.all = 0x2040; // Enable RXFIFO, clear RXFFINT,
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19 |
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20 | return;
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21 | }
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22 |
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23 |
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24 |
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25 | // Initialization of Input/Output ports
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26 | void init_gpio(void)
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27 | {
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28 |
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29 | // GPIO-32 - PIN FUNCTION = I2C SDA
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30 | GpioCtrlRegs.GPBPUD.bit.GPIO32 = 0;// Enable pull-up for GPIO32 (SDAA)
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31 | GpioCtrlRegs.GPBQSEL1.bit.GPIO32 = 3; // Asynch input GPIO32 (SDAA)
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32 | GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 1;//0; // 0=GPIO, 1=I2C-SDA, 2=SYNCI, 3=ADCSOCA
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33 | //GpioCtrlRegs.GPBDIR.bit.GPIO32 = 1; // 1=OUTput, 0=INput
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34 |
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35 | // GPIO-33 - PIN FUNCTION = I2C SCL
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36 | GpioCtrlRegs.GPBPUD.bit.GPIO33 = 0; // Enable pull-up for GPIO33 (SCLA)
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37 | GpioCtrlRegs.GPBQSEL1.bit.GPIO33 = 3; // Asynch input GPIO33 (SCLA)
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38 | GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 1;//0; // 0=GPIO, 1=I2C-SCL, 2=SYNCO, 3=ADCSOCB
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39 | //GpioCtrlRegs.GPBDIR.bit.GPIO33 = 1; // 1=OUTput, 0=INput
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40 |
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41 | }
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42 |
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43 |
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44 | //deactivate ADC intrrupt for test, activate I2C interrupt
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45 | I2c_interrupt_init()
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46 | {
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47 | // Disable CPU interrupts
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48 | DINT;
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49 |
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50 | // Disable CPU interrupts and clear all CPU interrupt //flags:
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51 | IER = 0x0000;
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52 | IFR = 0x0000;
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53 |
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54 | // Initialize the PIE vector table with pointers to the //shell Interrupt
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55 | // Service Routines (ISR).
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56 | // This will populate the entire table, even if the //interrupt
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57 | // is not used in this example. This is useful for debug //purposes.
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58 | // The shell ISR routines are found in //DSP280x_DefaultIsr.c.
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59 | // This function is found in DSP280x_PieVect.c.
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60 | // InitPieVectTable();
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61 |
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62 |
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63 | // Enable the PIE Vector Table
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64 | PieCtrlRegs.PIECTRL.bit.ENPIE = 1;
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65 |
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66 | // Interrupts that are used in this example are re-mapped //to
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67 | // ISR functions found within this file.
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68 | EALLOW; // This is needed to write to EALLOW //protected registers
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69 | PieVectTable.I2CINT1A = &i2c_int1a_isr;
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70 | EDIS; // This is needed to disable write to EALLOW //protected registers
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71 |
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72 |
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73 | // Enable I2C interrupt 1 in the PIE: Group 8 interrupt 1
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74 | PieCtrlRegs.PIEIER8.bit.INTx1 = 1;
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75 |
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76 | // Enable CPU INT8 which is connected to PIE group 8
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77 | IER |= M_INT8;
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78 | EINT;
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79 | }
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80 |
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81 |
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82 | // Endlosschleife
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83 | for(;;)
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84 | {
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85 | if(i2c_sent == 0)
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86 | I2C_communication();
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87 | }
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88 |
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89 | void I2C_communication()
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90 | {
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91 |
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92 | i2c_sent = 1;
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93 | // Send slave address with 1 as last bit for Read command
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94 | // 0101111(1) == 0x5F
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95 | I2caRegs.I2CSAR = I2C_READ_SLAVE_ADDRESS;
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96 | }
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97 |
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98 | interrupt void i2c_int1a_isr(void) // I2C-A
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99 | {
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100 | Uint16 IntSource;//, i;
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101 |
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102 | // Read interrupt source
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103 | IntSource = I2caRegs.I2CISRC.all;
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104 |
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105 | // Interrupt source = stop condition detected
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106 | if(IntSource == I2C_SCD_ISRC)
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107 | {
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108 | // If completed message was writing data, reset msg to inactive state
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109 | if (CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_WRITE_BUSY)
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110 | {
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111 | CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_INACTIVE;
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112 | }
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113 | }
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114 | else if(IntSource == I2C_ARDY_ISRC)
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115 | {
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116 | // NACK a no-acknowledge bit was sent during the //acknowledge
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117 | // cycle on the I2C-bus.
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118 | if(I2caRegs.I2CSTR.bit.NACK == 1)
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119 | {
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120 | // STP has been set by the device to generate a STOP condition
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121 | // when the internal data counter of the I2C module counts down to //0
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122 | I2caRegs.I2CMDR.bit.STP = 1;
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123 | // (1) NACK bit received. The hardware detects that a //no-acknowledge
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124 | // (NACK) bit has been received. Note: While the I2C module //performs
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125 | // a general call transfer, NACK is 1, even if one or more slaves
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126 | // send acknowledgment.
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127 | I2caRegs.I2CSTR.all = I2C_CLR_NACK_BIT;
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128 | }
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129 | else if(CurrentMsgPtr->MsgStatus == I2C_MSGSTAT_SEND_NOSTOP_BUSY)
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130 | {
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131 | CurrentMsgPtr->MsgStatus = I2C_MSGSTAT_RESTART;
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132 | }
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133 | } // end of register access ready
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134 |
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135 | else
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136 | {
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137 | // Generate some error due to invalid interrupt source
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138 | asm(" ESTOP0");
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139 | }
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140 |
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141 | i2c_sent = 0;
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142 |
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143 | // Enable future I2C (PIE Group 8) interrupts
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144 | PieCtrlRegs.PIEACK.all = PIEACK_GROUP8;
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145 | }
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