Mike Moore / mmSPI

SPI library used to communicate with an altera development board attached to four zigbee-header pins.

mmSPI.cpp@22:7524dee5c753, 2013-08-20 (annotated)

Committer:
gatedClock
Date:
Tue Aug 20 14:13:32 2013 +0000
Revision:
22:7524dee5c753
Parent:
21:e90dd0f8aaa1
Child:
23:dbd89a56716d
cleanup.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gatedClock 0:fb42c5acf810 1 /*----------------------------------------------//------------------------------
gatedClock 0:fb42c5acf810 2 student : m-moore
gatedClock 0:fb42c5acf810 3 class : external SPI interface
gatedClock 0:fb42c5acf810 4 directory : mmSPI
gatedClock 0:fb42c5acf810 5 file : mmSPI.cpp
gatedClock 0:fb42c5acf810 6 ------------------------------------------------//----------------------------*/
gatedClock 0:fb42c5acf810 7 #include "mmSPI.h"
gatedClock 0:fb42c5acf810 8 /*----------------------------------------------//------------------------------
gatedClock 0:fb42c5acf810 9 ------------------------------------------------//----------------------------*/
gatedClock 0:fb42c5acf810 10 //==============================================//==============================
gatedClock 15:d6cc57c4e23d 11 // consider resetting the fpga around here, because
gatedClock 15:d6cc57c4e23d 12 // the micro may be wiggling these signals before here.
gatedClock 0:fb42c5acf810 13 mmSPI::mmSPI() // constructor.
gatedClock 0:fb42c5acf810 14 {
gatedClock 3:de99451ab3c0 15 allocations(); // object allocations.
gatedClock 15:d6cc57c4e23d 16
gatedClock 15:d6cc57c4e23d 17 *pSCLK = 0; // initialize.
gatedClock 15:d6cc57c4e23d 18 *pCPUclk = 0; // initialize.
gatedClock 0:fb42c5acf810 19 }
gatedClock 0:fb42c5acf810 20 //----------------------------------------------//------------------------------
gatedClock 0:fb42c5acf810 21 mmSPI::~mmSPI() // destructor.
gatedClock 0:fb42c5acf810 22 {
gatedClock 8:e2d8bbc3e659 23 // deallocations.
gatedClock 8:e2d8bbc3e659 24 if (pMOSI) {delete pMOSI; pMOSI = NULL;}
gatedClock 8:e2d8bbc3e659 25 if (pMISO) {delete pMISO; pMISO = NULL;}
gatedClock 8:e2d8bbc3e659 26 if (pSCLK) {delete pSCLK; pSCLK = NULL;}
gatedClock 8:e2d8bbc3e659 27 if (pCPUclk) {delete pCPUclk; pCPUclk = NULL;}
gatedClock 3:de99451ab3c0 28 }
gatedClock 3:de99451ab3c0 29 //----------------------------------------------//------------------------------
gatedClock 3:de99451ab3c0 30 void mmSPI::allocations(void) // object allocations.
gatedClock 3:de99451ab3c0 31 {
gatedClock 8:e2d8bbc3e659 32 pMOSI = new DigitalOut(mmSPI_MOSI); // SPI MOSI pin object.
gatedClock 3:de99451ab3c0 33 if (!pMOSI) error("\n\r mmSPI::allocations : FATAL malloc error for pMOSI. \n\r");
gatedClock 3:de99451ab3c0 34
gatedClock 8:e2d8bbc3e659 35 pMISO = new DigitalOut(mmSPI_MISO); // SPI MISO pin object.
gatedClock 3:de99451ab3c0 36 if (!pMISO) error("\n\r mmSPI::allocations : FATAL malloc error for pMISO. \n\r");
gatedClock 3:de99451ab3c0 37
gatedClock 8:e2d8bbc3e659 38 pSCLK = new DigitalOut(mmSPI_SCLK); // SPI SCLK pin object.
gatedClock 3:de99451ab3c0 39 if (!pSCLK) error("\n\r mmSPI::allocations : FATAL malloc error for pSCLK. \n\r");
gatedClock 8:e2d8bbc3e659 40
gatedClock 8:e2d8bbc3e659 41 pCPUclk = new DigitalOut(mmCPU_CLK); // SPI SCLK pin object.
gatedClock 8:e2d8bbc3e659 42 if (!pCPUclk) error("\n\r mmSPI::allocations : FATAL malloc error for pCPUclk. \n\r");
gatedClock 3:de99451ab3c0 43 }
gatedClock 4:aa1fe8707bef 44 //----------------------------------------------//------------------------------
gatedClock 4:aa1fe8707bef 45 void mmSPI::setSPIfrequency(float fFreq) // set SPI clock frequency.
gatedClock 4:aa1fe8707bef 46 {
gatedClock 4:aa1fe8707bef 47 fSPIfreq = fFreq; // promote to object scope.
gatedClock 4:aa1fe8707bef 48 if (fSPIfreq < .05) // don't get near divide-by-zero.
gatedClock 4:aa1fe8707bef 49 error("\n\r mmSPI::setSPIfrequency : FATAL SPI frequency set too low. \n\r");
gatedClock 4:aa1fe8707bef 50 fSPIquarterP = (1 / fSPIfreq) / 4; // figure quarter-cycle period.
gatedClock 4:aa1fe8707bef 51 }
gatedClock 22:7524dee5c753 52 //----------------------------------------------//------------------------------
gatedClock 22:7524dee5c753 53 // obtain SPI send buffer pointer.
gatedClock 22:7524dee5c753 54 void mmSPI::setSendBuffer(char * pcSendBuffer)
gatedClock 22:7524dee5c753 55 {
gatedClock 22:7524dee5c753 56 pcSend = pcSendBuffer; // promote to object scope.
gatedClock 22:7524dee5c753 57 }
gatedClock 22:7524dee5c753 58 //----------------------------------------------//------------------------------
gatedClock 22:7524dee5c753 59 // obtain SPI receive buffer pointer.
gatedClock 22:7524dee5c753 60 void mmSPI::setReceiveBuffer(char * pcReceiveBuffer)
gatedClock 22:7524dee5c753 61 {
gatedClock 22:7524dee5c753 62 pcReceive = pcReceiveBuffer; // promote to object scope.
gatedClock 22:7524dee5c753 63 }
gatedClock 0:fb42c5acf810 64 //----------------------------------------------//------------------------------
gatedClock 22:7524dee5c753 65 // obtain number of SPI bytes.
gatedClock 22:7524dee5c753 66 void mmSPI::setNumberOfBytes(int dNumberOfBytes)
gatedClock 22:7524dee5c753 67 {
gatedClock 22:7524dee5c753 68 dNumBytes = dNumberOfBytes; // promote to object scope.
gatedClock 22:7524dee5c753 69 }
gatedClock 22:7524dee5c753 70 //----------------------------------------------//------------------------------
gatedClock 22:7524dee5c753 71
gatedClock 22:7524dee5c753 72
gatedClock 22:7524dee5c753 73
gatedClock 22:7524dee5c753 74
gatedClock 16:0e422fd263c6 75 // transceive a character array.
gatedClock 16:0e422fd263c6 76 // limit is 256 characters.
gatedClock 16:0e422fd263c6 77 // MSB out/in first.
gatedClock 22:7524dee5c753 78 void mmSPI::transceive_vector(char *pcReceive, char *pcSend, int dNumBytes)
gatedClock 16:0e422fd263c6 79 {
gatedClock 16:0e422fd263c6 80 int dClear;
gatedClock 16:0e422fd263c6 81 int dIndex;
gatedClock 16:0e422fd263c6 82 int dMosiByteIndex;
gatedClock 16:0e422fd263c6 83 int dMosiBitIndex;
gatedClock 16:0e422fd263c6 84 int dMisoByteIndex;
gatedClock 16:0e422fd263c6 85 int dMisoBitIndex;
gatedClock 16:0e422fd263c6 86
gatedClock 16:0e422fd263c6 87 dIndex = (dNumBytes * 8) - 1;
gatedClock 16:0e422fd263c6 88 dMosiByteIndex = dIndex / 8;
gatedClock 16:0e422fd263c6 89 dMosiBitIndex = dIndex % 8;
gatedClock 16:0e422fd263c6 90
gatedClock 16:0e422fd263c6 91 for (dClear = 0; dClear < dNumBytes; dClear++) pcReceive[dClear] = 0;
gatedClock 16:0e422fd263c6 92
gatedClock 16:0e422fd263c6 93
gatedClock 16:0e422fd263c6 94 *pCPUclk = 1; // pulse the CPU clock.
gatedClock 16:0e422fd263c6 95 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 96 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 97 *pCPUclk = 0;
gatedClock 16:0e422fd263c6 98 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 99 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 100
gatedClock 16:0e422fd263c6 101 *pSCLK = 1; // pulse the SPI clock for parallel load.
gatedClock 16:0e422fd263c6 102 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 103 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 104 *pSCLK = 0;
gatedClock 16:0e422fd263c6 105 // pre-assert MOSI.
gatedClock 16:0e422fd263c6 106 *pMOSI = ((pcSend[dMosiByteIndex]) >> dMosiBitIndex) & 1;
gatedClock 16:0e422fd263c6 107 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 108 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 109
gatedClock 16:0e422fd263c6 110
gatedClock 16:0e422fd263c6 111 for (dIndex = (dNumBytes * 8) - 1; dIndex >= 0; dIndex--)
gatedClock 16:0e422fd263c6 112 {
gatedClock 16:0e422fd263c6 113 dMisoByteIndex = dIndex / 8;
gatedClock 16:0e422fd263c6 114 dMisoBitIndex = dIndex % 8;
gatedClock 18:4a29cad91540 115 pcReceive[dMisoByteIndex] = pcReceive[dMisoByteIndex] | (*pMISO << dMisoBitIndex);
gatedClock 16:0e422fd263c6 116 *pSCLK = 1;
gatedClock 16:0e422fd263c6 117 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 118 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 119 *pSCLK = 0;
gatedClock 16:0e422fd263c6 120
gatedClock 16:0e422fd263c6 121 if (dIndex < 0) dIndex = 0;
gatedClock 16:0e422fd263c6 122 dMosiByteIndex = (dIndex - 1) / 8;
gatedClock 16:0e422fd263c6 123 dMosiBitIndex = (dIndex - 1) % 8;
gatedClock 16:0e422fd263c6 124 *pMOSI = ((pcSend[dMosiByteIndex]) >> dMosiBitIndex) & 1;
gatedClock 16:0e422fd263c6 125 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 126 wait(fSPIquarterP);
gatedClock 16:0e422fd263c6 127 }
gatedClock 7:b3e8b537d5c2 128 }
gatedClock 7:b3e8b537d5c2 129 //----------------------------------------------//------------------------------
gatedClock 16:0e422fd263c6 130 void mmSPI::write_register(char cRegister, char cValue, char * pcReceive, char * pcSend)
gatedClock 16:0e422fd263c6 131 {
gatedClock 18:4a29cad91540 132 int dLoop; // loop index.
gatedClock 18:4a29cad91540 133
gatedClock 18:4a29cad91540 134 // clear transmit vector.
gatedClock 18:4a29cad91540 135 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 18:4a29cad91540 136
gatedClock 18:4a29cad91540 137 pcSend[7] = 0x02; // mbed sends a command.
gatedClock 18:4a29cad91540 138
gatedClock 18:4a29cad91540 139 // align into instruction word.
gatedClock 16:0e422fd263c6 140 pcSend[1] = ((cRegister & 0x07) << 2) | 0xA0;
gatedClock 18:4a29cad91540 141 pcSend[0] = cValue & 0xFF; // immediate value to i.w.
gatedClock 17:b81c0c1f312f 142
gatedClock 22:7524dee5c753 143 transceive_vector(pcReceive, pcSend, 8); // transmit command.
gatedClock 18:4a29cad91540 144
gatedClock 18:4a29cad91540 145 // clear transmit vector.
gatedClock 18:4a29cad91540 146 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 17:b81c0c1f312f 147 }
gatedClock 17:b81c0c1f312f 148 //----------------------------------------------//------------------------------
gatedClock 17:b81c0c1f312f 149 // returns the content of
gatedClock 17:b81c0c1f312f 150 // a CPU register.
gatedClock 17:b81c0c1f312f 151 char mmSPI::read_register(char cRegister, char * pcReceive, char * pcSend)
gatedClock 17:b81c0c1f312f 152 {
gatedClock 19:c2b753533b93 153 int dLoop;
gatedClock 21:e90dd0f8aaa1 154
gatedClock 19:c2b753533b93 155
gatedClock 21:e90dd0f8aaa1 156 // send all 0.
gatedClock 18:4a29cad91540 157 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 18:4a29cad91540 158
gatedClock 22:7524dee5c753 159 transceive_vector(pcReceive, pcSend, 8); // snap & scan-out reg contents.
gatedClock 17:b81c0c1f312f 160
gatedClock 19:c2b753533b93 161 return (pcReceive[6 - cRegister]); // return the particular reg value.
gatedClock 17:b81c0c1f312f 162 }
gatedClock 17:b81c0c1f312f 163 //----------------------------------------------//------------------------------
gatedClock 18:4a29cad91540 164 void mmSPI::write_memory(char cHData, char cLdata, char cAddress, char * pcReceive, char * pcSend)
gatedClock 18:4a29cad91540 165 {
gatedClock 18:4a29cad91540 166 int dLoop; // loop index.
gatedClock 18:4a29cad91540 167
gatedClock 18:4a29cad91540 168 // clear transmit vector.
gatedClock 18:4a29cad91540 169 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 19:c2b753533b93 170
gatedClock 18:4a29cad91540 171 // R3 <- address.
gatedClock 18:4a29cad91540 172 // R2 <- high-data.
gatedClock 18:4a29cad91540 173 // R1 <- low-data.
gatedClock 18:4a29cad91540 174 write_register(0x03,cAddress, pcReceive, pcSend);
gatedClock 20:2d5cd38047ca 175 write_register(0x02,cHData, pcReceive, pcSend);
gatedClock 20:2d5cd38047ca 176 write_register(0x01,cLdata, pcReceive, pcSend);
gatedClock 18:4a29cad91540 177
gatedClock 20:2d5cd38047ca 178 pcSend[7] = 0x00; // write-enable high.
gatedClock 20:2d5cd38047ca 179 pcSend[1] = 0x02;
gatedClock 20:2d5cd38047ca 180 pcSend[0] = 0x00;
gatedClock 22:7524dee5c753 181 transceive_vector(pcReceive, pcSend, 8);
gatedClock 18:4a29cad91540 182
gatedClock 20:2d5cd38047ca 183 pcSend[7] = 0x00; // write-enable low.
gatedClock 20:2d5cd38047ca 184 pcSend[1] = 0x00;
gatedClock 20:2d5cd38047ca 185 pcSend[0] = 0x00;
gatedClock 22:7524dee5c753 186 transceive_vector(pcReceive, pcSend, 8);
gatedClock 18:4a29cad91540 187
gatedClock 18:4a29cad91540 188 // clear transmit vector.
gatedClock 18:4a29cad91540 189 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 19:c2b753533b93 190
gatedClock 18:4a29cad91540 191 }
gatedClock 18:4a29cad91540 192 //----------------------------------------------//------------------------------
gatedClock 18:4a29cad91540 193 // fetch a word from main memory.
gatedClock 18:4a29cad91540 194 unsigned int mmSPI::read_memory(char cAddress, char * pcReceive, char * pcSend)
gatedClock 18:4a29cad91540 195 {
gatedClock 18:4a29cad91540 196 int dLoop; // loop index.
gatedClock 18:4a29cad91540 197 unsigned int udMemoryContent; // return variable.
gatedClock 18:4a29cad91540 198 char cHData; // returned data-high.
gatedClock 18:4a29cad91540 199 char cLData; // returned data-low.
gatedClock 18:4a29cad91540 200
gatedClock 18:4a29cad91540 201 // clear transmit vector.
gatedClock 18:4a29cad91540 202 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 21:e90dd0f8aaa1 203
gatedClock 19:c2b753533b93 204
gatedClock 18:4a29cad91540 205 // R3 <- address.
gatedClock 18:4a29cad91540 206 write_register(0x03,cAddress, pcReceive, pcSend);
gatedClock 18:4a29cad91540 207
gatedClock 18:4a29cad91540 208 pcSend[7] = 0x02; // mbed sends command.
gatedClock 20:2d5cd38047ca 209 pcSend[1] = 0xC8; // R2 <- MM[R3]
gatedClock 18:4a29cad91540 210 pcSend[0] = 0x00;
gatedClock 22:7524dee5c753 211 transceive_vector(pcReceive, pcSend, 8); // send command.
gatedClock 18:4a29cad91540 212
gatedClock 18:4a29cad91540 213 pcSend[7] = 0x02; // mbed sends command.
gatedClock 20:2d5cd38047ca 214 pcSend[1] = 0xC4; // R1 <- MM[R3]
gatedClock 18:4a29cad91540 215 pcSend[0] = 0x00;
gatedClock 22:7524dee5c753 216 transceive_vector(pcReceive, pcSend, 8); // send command.
gatedClock 18:4a29cad91540 217
gatedClock 18:4a29cad91540 218 // obtain MM content.
gatedClock 20:2d5cd38047ca 219 cHData = read_register(0x02, pcReceive, pcSend);
gatedClock 20:2d5cd38047ca 220 cLData = read_register(0x01, pcReceive, pcSend);
gatedClock 18:4a29cad91540 221
gatedClock 18:4a29cad91540 222
gatedClock 18:4a29cad91540 223 udMemoryContent = (cHData << 8) + cLData; // build the memory word.
gatedClock 18:4a29cad91540 224
gatedClock 18:4a29cad91540 225 // clear transmit vector.
gatedClock 18:4a29cad91540 226 for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
gatedClock 18:4a29cad91540 227
gatedClock 18:4a29cad91540 228 return udMemoryContent; // return the memory word.
gatedClock 18:4a29cad91540 229 }
gatedClock 18:4a29cad91540 230 //----------------------------------------------//------------------------------
gatedClock 17:b81c0c1f312f 231
gatedClock 17:b81c0c1f312f 232
gatedClock 5:b14dcaae260e 233
gatedClock 5:b14dcaae260e 234
gatedClock 5:b14dcaae260e 235
gatedClock 5:b14dcaae260e 236
gatedClock 5:b14dcaae260e 237
gatedClock 5:b14dcaae260e 238
gatedClock 5:b14dcaae260e 239
gatedClock 7:b3e8b537d5c2 240
gatedClock 7:b3e8b537d5c2 241
gatedClock 7:b3e8b537d5c2 242
gatedClock 7:b3e8b537d5c2 243
gatedClock 7:b3e8b537d5c2 244
gatedClock 15:d6cc57c4e23d 245