SWSPI_BI.cpp

00001 /* SWSPI, Software SPI library
00002  * Copyright (c) 2012-2014, David R. Van Wagner, http://techwithdave.blogspot.com
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  
00022  
00023   * modified the software for adapt to the AD9249 ADC  ( bi directional ) with LVDS interface 
00024   * Software adapted for the SM1 project of the SOLID colaboration 
00025   * (C) Wim Beaumont Univeristeit Antwerpen  2014 , 2015  
00026     
00027  */ 
00028 
00029 #include <mbed.h>
00030 #include "SWSPI_BI.h"
00031 #include "S_SCTRL_SM1_hwfunct.h"
00032 
00033 #define SWSPI_BI_SRC_VER  "1.50"
00034 
00035 /** 
00036     PARAM
00037     @misopin pointer to the input / output pin for the data communication
00038     @rdir_pin  pointer to the output pin that sets the remote LVDS buffer to read / write 
00039     @ldir_pin  pointer to the output pin that sets the local  LVDS buffer to read / write  
00040     @sclk_pin  pointer to the output pin that act as the clock signal for the interface 
00041     
00042 */
00043 SWSPI_BI::SWSPI_BI(DigitalInOut *msio_pin, DigitalOut *rdir_pin,DigitalOut *ldir_pin, DigitalOut *sclk_pin) 
00044     :getVersion( SWSPI_BI_HDR_VER , SWSPI_BI_SRC_VER , __TIME__, __DATE__)
00045 {
00046     
00047     msio = msio_pin;
00048     rdir = rdir_pin;
00049     ldir = ldir_pin;
00050     sclk = sclk_pin;
00051     set_bi_spi_mo(1, msio,ldir,rdir);
00052     
00053     format(8);
00054     frequency(500000);
00055 }
00056 
00057 SWSPI_BI::~SWSPI_BI()
00058 {
00059 }
00060 
00061 void SWSPI_BI::format( int bitsin, int modein ){
00062     bits = bitsin;
00063     mode = modein;
00064     polarity = !((modein >> 1) & 1);
00065     phase = modein & 1;
00066     sclk->write(polarity);
00067 }
00068 
00069 void SWSPI_BI::frequency(int hz)
00070 {
00071     this->freq = hz;
00072 }
00073 
00074 void  SWSPI_BI::write(unsigned int value, DigitalOut * cs, bool lastdata, int cs_pol,bool nxtrd ){
00075 
00076     // write data to output 
00077     // assumption is that the cs line was just set from high to low so that the SPI slave is in read mode 
00078         value= ~value;    
00079         set_bi_spi_mo(1,msio,ldir,rdir);        
00080         cs->write(cs_pol); 
00081         for (int bit = bits-1; bit >= 0; --bit)    {
00082             msio->write(((value >> bit) & 0x01) != 0);
00083             if(phase) {   sclk->write(!polarity);   wait(1.0/freq/2); sclk->write(polarity); 
00084                     if(!bit and nxtrd) set_bi_spi_mo(0,msio,ldir,rdir); // set already to input mode 
00085                      wait(1.0/freq/2);    }
00086             else  { wait(1.0/freq/2);  sclk->write(!polarity);  wait(1.0/freq/2);  sclk->write(polarity);      }
00087           
00088           
00089         }
00090         if( lastdata) {
00091             set_bi_spi_mo(0,msio,ldir,rdir); 
00092             cs->write(!cs_pol); 
00093         }
00094         else {
00095         }
00096 }        
00097 
00098 unsigned int  SWSPI_BI::read( DigitalOut * cs, bool lastdata, int cs_pol ){
00099     unsigned int read = 0;    
00100     set_bi_spi_mo(0,msio,ldir,rdir);        
00101     cs->write(cs_pol); 
00102     wait(1.0/freq/2);
00103     for (int bit = bits-1; bit >= 0; --bit)  {
00104         if (phase == 0) {
00105             if (msio->read())  read |= (1 << bit);
00106                
00107         }
00108         sclk->write(!polarity);
00109         wait(1.0/freq/2);
00110         if (phase == 1) {
00111             if (msio->read()) read |= (1 << bit);            
00112         }
00113 
00114         sclk->write(polarity);
00115         wait(1.0/freq/2);
00116     }
00117     if( lastdata) {    
00118             cs->write(!cs_pol); 
00119     }
00120     // else keep current io config 
00121    
00122     
00123     return ~read;
00124 }
00125