Tedd OKANO
I2C fast mode plus support library. This library works on mbed-11U24's p28&p27 only.
A sample code for I2C Fast mode plus operation.
Warning!
This code works on mbed-LPC11U24 only.
Import programI2C_FmPlus_Hello
Sample code for "I2C_FmPlus" library. I2C fast mode plus support library. This library works on mbed-11U24's p28&p27 only.
Last commit 02 Dec 2014 by 
Tedd OKANO
Diff: I2C_FmPlus.cpp
- Revision:
- 1:6d19e8abca69
- Parent:
- 0:213903402306
- Child:
- 2:16a05acd675b
--- a/I2C_FmPlus.cpp Tue Dec 02 01:17:19 2014 +0000
+++ b/I2C_FmPlus.cpp Tue Dec 02 03:57:29 2014 +0000
@@ -2,17 +2,14 @@
*
* @class I2C_FmPlus
* @author tedd
- * @version 0.9
- * @date 13-Jul-2012
- *
- * Released under the MIT License: http://mbed.org/license/mit
- *
+ * @version 1.0
+ * @date 02-Dec-2014
*/
#include "mbed.h"
#include "I2C_FmPlus.h"
-I2C_FmPlus::I2C_FmPlus( PinName sda, PinName scl, const char *name ) : I2C( sda, scl, name )
+I2C_FmPlus::I2C_FmPlus( PinName sda, PinName scl ) : I2C( sda, scl ), _frequency( 1000 * 1000 ), _ratio( 0.4 )
{
LPC_IOCON->PIO0_4 &= ~0x300;
LPC_IOCON->PIO0_4 |= 0x200;
@@ -20,8 +17,27 @@
LPC_IOCON->PIO0_5 |= 0x200;
}
+void I2C_FmPlus::frequency( float hz ) {
+ _frequency = hz;
+ uint32_t pclk = SystemCoreClock;
+ float i2c_scl_period = (1.0 / hz) - 100e-9; // for SCLH offset and rise/fall time conpensation;
+ float scl_period_in_clock = (float)pclk * i2c_scl_period;
+ uint32_t low_period = scl_period_in_clock * (1.0 - _ratio);
+ uint32_t high_period = scl_period_in_clock * _ratio;
+ // I2C Rate
+ LPC_I2C->SCLL = low_period < 4 ? 4 : low_period;
+ LPC_I2C->SCLH = high_period < 4 ? 4 : high_period;
+}
+
+void I2C_FmPlus::duty_ratio( float ratio ) {
+ _ratio = ratio;
+ frequency( _frequency );
+}
+
+#if 0
void I2C_FmPlus::scl_setting( char sclh, char scll )
{
LPC_I2C->SCLH = sclh;
LPC_I2C->SCLL = scll;
}
+#endif