Revision 0:46b1b63c40e6, committed 2013-10-30

Comitter:

henryeherman

Date:

Wed Oct 30 18:15:52 2013 +0000

Commit message:

Shift register for driving chip select lines on Elixys Synthesizer board

Changed in this revision

diff -r 000000000000 -r 46b1b63c40e6 ShiftRegister.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ShiftRegister.cpp	Wed Oct 30 18:15:52 2013 +0000
@@ -0,0 +1,34 @@
+#include "mbed.h"
+#include "ShiftRegister.h"
+
+using namespace mbed;
+
+ShiftRegister::ShiftRegister(DigitalOut &clk, DigitalOut &dat, 
+                DigitalOut &latch, DigitalOut &clr, 
+                DigitalOut &oe): _clk(clk), _dat(dat),
+                                    _latch(latch), _clr(clr),
+                                    _oe(oe) {
+                                    
+    _clk = 1;
+    _dat = 1;
+    _clr = 0;
+    _oe = 1;     
+    _clr = 1;
+    _oe = 0;   
+}
+
+ShiftRegister::~ShiftRegister() {
+    // Nothing to do!
+    clear();
+}
+
+
+
+void ShiftRegister::clear() {
+    _clk = 1;
+    _dat = 1;
+    _clr = 0;
+    _oe = 1;     
+    _clr = 1;
+    _oe = 0;  
+}
\ No newline at end of file

diff -r 000000000000 -r 46b1b63c40e6 ShiftRegister.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ShiftRegister.h	Wed Oct 30 18:15:52 2013 +0000
@@ -0,0 +1,56 @@
+#include "mbed.h"
+#ifndef SHIFTREGISTER_H
+#define SHIFTREGISTER_H
+
+
+class ShiftRegister {
+
+public:
+
+/*
+* Constructor
+*/
+ShiftRegister(DigitalOut &clk, DigitalOut &dat, 
+                DigitalOut &latch, DigitalOut &clr, 
+                DigitalOut &oe);
+
+/*
+* Destructor
+*/
+~ShiftRegister();
+
+/*
+* Write Value
+*/
+template <typename T>
+int write(T val, int bits);
+
+void clear();
+
+private:
+DigitalOut &_clk;
+DigitalOut &_dat;
+DigitalOut &_latch;
+DigitalOut &_clr;
+DigitalOut &_oe;
+
+}; // end class ShiftRegister
+
+
+template <typename T>
+int ShiftRegister::write(T val, int bits) {        
+    T tmpval = ~0;
+    int tmpsz = sizeof(val)*8;
+    val = tmpval & val;  
+    bits = tmpsz < bits ? tmpsz : bits;
+    for(char i = 0; i < bits; i++) {
+        _dat.write((val >> i) & 0x01);        
+        _clk = 0;        
+        _clk = 1;
+    }
+    _latch = 0; 
+    _latch =1;
+    return val;
+}
+
+#endif //ShiftRegister
\ No newline at end of file