Content originally posted in LPCWare by Patrick_W on Wed Apr 29 00:57:31 MST 2015 Hey Guys,
On my board i am using a LPC1763 and i connected a switch with external pulldown resistors to Port 1 Pin16-19. I wanted to read in the value of this pins but i always read high (internal pullup is on by default). So i used the Chip_IOCON_PinMux to switch of the internal Pullup resistor like this:
But during debugging i saw that in the PINMODE Register the value is first set correctly and after setting the next pin, the value is again overwritten (default mode again = pullup). So i checked the definition of IOCON_MODE_INACT:
#if defined(CHIP_LPC175X_6X)
#define IOCON_MODE_INACT (0x2 << 2)/*!< No addition pin function */
So the value is 8. I then changed my code to this:
The value 2 is written in the manual (page 114) With the change my code behave like expected (PINMODE Register set correct).
So can anybody explain me the thought behind the definition of IOCON_MODE_INACT? Because it seems to be wrong in my case or had somebody the same problem?
Content originally posted in LPCWare by R2D2 on Wed Apr 29 01:49:13 MST 2015 Quote: Patrick_W Because it seems to be wrong in my case...
That's wrong in any case
/**
* IOCON function and mode selection definitions
* See the User Manual for specific modes and [color=#f00]functions supoprted by the
* various LPC11xx devices. Functionality can vary per device.
[/color] */
#define IOCON_FUNC0 0x0/*!< Selects pin function 0 */
#define IOCON_FUNC1 0x1/*!< Selects pin function 1 */
#define IOCON_FUNC2 0x2/*!< Selects pin function 2 */
#define IOCON_FUNC3 0x3/*!< Selects pin function 3 */
#if defined(CHIP_LPC175X_6X)
[color=#f00]#define IOCON_MODE_INACT (0x2 << 2)/*!< No addition pin function */
#define IOCON_MODE_PULLDOWN (0x3 << 2)/*!< Selects pull-down function */
#define IOCON_MODE_PULLUP (0x0 << 2)/*!< Selects pull-up function */
#define IOCON_MODE_REPEATER (0x1 << 2)/*!< Selects pin repeater function */
[/color]#else
Obviously that's an old copy from LPC11xx and LPC17xx is not 'supoprted', so functionality is varying here
