Revision 1:8064f8b8cf82, committed 2010-05-22

Comitter:

igorsk

Date:

Sat May 22 22:58:38 2010 +0000

Parent:

0:f1e54c45ccaf

Child:

2:9c4a8c01862c

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FastIO.h	Sat May 22 22:58:38 2010 +0000
@@ -0,0 +1,100 @@
+#ifndef __FAST_IO_H
+#define __FAST_IO_H
+
+#include "mbed.h"
+
+// Super-fast DigitalOut-like class for mbed
+//   by Igor Skochinsky
+
+// pin definitions in PinNames.h start from LPC_GPIO0_BASE for P0_0 and there are 32 pins to a port (0 to 31)
+// Thus:
+// pin = LPC_GPIO0_BASE + port * 32 + bit
+// port = (pin - LPC_GPIO0_BASE) / 32
+// bit  = (pin - LPC_GPIO0_BASE) % 32
+
+#define PORTNO(pin) (((pin) - P0_0)/32)
+#define BITNO(pin)  (((pin) - P0_0)%32)
+
+// calculate the GPIO port definition for the pin
+// we rely on the fact that port structs are 0x20 bytes apart
+#define PORTDEF(pin) ((LPC_GPIO_TypeDef*)(LPC_GPIO0_BASE + PORTNO(pin)*0x20))
+
+#define PORTDEFPORT(port) ((LPC_GPIO_TypeDef*)(LPC_GPIO0_BASE + port*0x20))
+
+// calculate the mask for the pin's bit in the port
+#define PINMASK(pin) (1UL << BITNO(pin))
+
+// each port takes two PINSEL registers (8 bytes or 64 bits)
+// so there are 16 pins per PINSEL
+#define PINSELREG(pin)  (*(volatile uint32_t*)(LPC_PINCON_BASE + 4*(((pin) - P0_0)/16)))
+#define PINSELMASK(pin, v) (v << (((pin - P0_0)%16)*2) )
+
+// usage: FastOut<LED2> led2;
+// then use the same assignment operators as with DigitalOut
+template <PinName pin> class FastOut
+{
+public:
+    FastOut()
+    {
+        // set PINSEL bits to 0b00 (GPIO)
+        PINSELREG(pin) &= ~PINSELMASK(pin, 3);
+        // set FIODIR bit to 1 (output)
+        PORTDEF(pin)->FIODIR |= PINMASK(pin);
+    }
+    void write(int value)
+    { 
+        if ( value )
+            PORTDEF(pin)->FIOSET = PINMASK(pin);
+        else
+            PORTDEF(pin)->FIOCLR = PINMASK(pin);
+    } 
+    int read()
+    {
+        return PORTDEF(pin)->FIOPIN & PINMASK(pin) != 0;
+    }
+    FastOut& operator= (int value) { write(value); return *this; };
+    FastOut& operator= (FastOut& rhs) { return write(rhs.read()); };
+    operator int() { return read(); };
+};
+
+#define PINSELREG(pin)  (*(volatile uint32_t*)(LPC_PINCON_BASE + 4*(((pin) - P0_0)/16)))
+#define PINSELMASK(pin, v) (v << (((pin - P0_0)%16)*2) )
+
+// usage: FastPortOut<0> led2;
+// then use the same assignment operators as with DigitalOut
+template <enum PortName port, uint32_t mask = 0xFFFFFFFF> class FastPortOut
+{
+public:
+    FastPortOut()
+    {
+        // init pins selected by the mask
+        uint32_t pin = LPC_GPIO0_BASE + port * 32;
+        for ( uint32_t pinmask = mask; pinmask !=0; pinmask >>= 1 )
+        {
+            if ( pinmask & 1 )
+            {
+                // set PINSEL bits to 0b00 (GPIO)
+                PINSELREG(pin) &= ~PINSELMASK(pin, 3);
+                // set FIODIR bit to 1 (output)
+                PORTDEF(pin)->FIODIR |= PINMASK(pin);
+            }
+            pin++;
+        }
+    }
+    void write(int value)
+    {
+        if ( value & mask )
+            PORTDEFPORT(port)->FIOSET = value & mask;
+        if ( value & ~mask )
+            PORTDEFPORT(port)->FIOCLR = value & ~mask;
+    } 
+    int read()
+    {
+        return PORTDEFPORT(port)->FIOPIN & mask;
+    }
+    FastPortOut& operator= (int value) { write(value); return *this; };
+    FastPortOut& operator= (FastPortOut& rhs) { return write(rhs.read()); };
+    operator int() { return read(); };
+};
+
+#endif
\ No newline at end of file

--- a/main.cpp	Fri Mar 12 10:12:32 2010 +0000
+++ b/main.cpp	Sat May 22 22:58:38 2010 +0000
@@ -1,46 +1,13 @@
 #include "mbed.h"
-// Super-fast DigitalOut-like class for mbed
-//   by Igor Skochinsky
-
-// usage: FastOut<LED2> led2;
-// then use the same assignment operators as with DigitalOut
-template <PinName pin> class FastOut
-{
-// pin = LPC_GPIO0_BASE + port * 32 + bit
-// port = (pin - LPC_GPIO0_BASE) / 32
-// bit  = (pin - LPC_GPIO0_BASE) % 32
-    
-    // helper function to calculate the GPIO port definition for the pin
-    // we rely on the fact that port structs are 0x20 bytes apart
-    inline LPC_GPIO_TypeDef* portdef() { return (LPC_GPIO_TypeDef*)(LPC_GPIO0_BASE + ((pin - P0_0)/32)*0x20); };
-
-    // helper function to calculate the mask for the pin's bit in the port
-    inline uint32_t mask() { return 1UL<<((pin - LPC_GPIO0_BASE) % 32); };
 
-public:
-    FastOut()
-    {
-        // set FIODIR bit to 1 (output)
-        portdef()->FIODIR |= mask();
-    }
-    void write(int value)
-    { 
-        if ( value )
-            portdef()->FIOSET = mask();
-        else
-            portdef()->FIOCLR = mask();
-    } 
-    int read()
-    {
-        return (portdef()->FIOPIN) & mask() != 0;
-    }
-    FastOut& operator= (int value) { write(value); return *this; };
-    FastOut& operator= (FastOut& rhs) { return write(rhs.read()); };
-    operator int() { return read(); };
-};
+#include "FastIO.h"
+
+#define LED_MASK 0x07800000
 
 DigitalOut led1(LED1);
 FastOut<LED2> led2;
+PortOut ledport(Port0, LED_MASK);
+FastPortOut<Port0, LED_MASK> ledport2;
 
 Timer t;
 #define LOOPS 100000000
@@ -55,6 +22,7 @@
     }
     t.stop();
     printf("DigitalOut: %f seconds (%d ns per iteration).\n", t.read(), t.read_us()/(LOOPS/1000));
+    
     count = LOOPS;
     t.reset();
     t.start();
@@ -65,4 +33,28 @@
     }
     t.stop();
     printf("FastOut: %f seconds (%d ns per iteration).\n", t.read(), t.read_us()/(LOOPS/1000));
+
+    count = LOOPS;
+    t.reset();
+    t.start();
+    value = LED_MASK;
+    while ( count -- )
+    {
+        ledport.write(value);
+        value ^= LED_MASK;
+    }
+    t.stop();
+    printf("PortOut: %f seconds (%d ns per iteration).\n", t.read(), t.read_us()/(LOOPS/1000));
+
+    count = LOOPS;
+    t.reset();
+    t.start();
+    value = LED_MASK;
+    while ( count -- )
+    {
+        ledport2 = value;
+        value ^= LED_MASK;
+    }
+    t.stop();
+    printf("FastPortOut: %f seconds (%d ns per iteration).\n", t.read(), t.read_us()/(LOOPS/1000));
 }

--- a/mbed.bld	Fri Mar 12 10:12:32 2010 +0000
+++ b/mbed.bld	Sat May 22 22:58:38 2010 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/49a220cc26e0
+http://mbed.org/users/mbed_official/code/mbed/builds/e6be4cd80aad