Si4010-DK

12

Rev. 0.1

Facts about using the LED with IDE chain:

1.

The IDE chain can connect to the device only if the LED current driver is off and the LED is not lit.

2.

Once the IDE chain is connected to the device it blocks the device LED driver. Therefore, the application

can be written in a normal fashion using LED as desired in the final application without worry of being dis-

connected from the debug chain. The only limitation is that the LED will not be lit from the application dur-

ing the IDE debug session. The user will still observe LED activity, but that activity is related to the debug

chain communicating with the device, not the user application driving the LED.

3.

Once the IDE chain is disconnected from the device (for example, by pressing the Disconnect button in

the IDE), the device is released from halt and at the same time the blocking of the LED driver is removed.

From that point on, the application behaves and runs as a regular application and the LED activity reflects

what the application desires to do with the LED.

4.

If the user wants to reconnect the IDE to the device the only requirement is that the LED must not be lit by

the application and the C2 debug interface must be active, not being actively turned off by the application.

Therefore, if the device user software is stuck in an infinite loop and driving the LED constantly or the C2

interface was turned off by the application, the IDE chain will not be able to connect to the device. In such

a situation, the device power has to be cycled to invoke internal power on reset. (See item 1 above.)

Cycling the power to the part in this context means either physical removal of the power to the device or

calling the vSys_Shutdown() function from within the application, which achieves the same result.

2.8. Hardware Issue with Debugging LED Application

There is an issue with the LED turning on and off and the functionality of the GPI04. There is no issue when the

part is programmed as the Run part and runs the final application code. Therefore, the issue affects only the

application development. There are several possible software workarounds, depending on the approach the user

wants to take.

2.8.1. Application LED Control

The user can control the LED intensity and whether the LED is on or off. The LED intensity has 4 values, 0 to 3:

Off, 0.3 mA, 0.6 mA, and 1 mA current. The user can set the intensity any time, but the LED is not going to be

turned on until the GPIO_LED is set to 1. The GPIO_LED is an alias for the P0.5 bit.

After the reset the P0.5 bit is set to 1, so it is recommended that the user use GPIO_LED = 0 at the beginning of the

user application.

To turn the LED off at the very beginning of the user application:

/* Clear the GPIO_LED.. reset will set this bit! */

GPIO_LED = 0;

To turn the LED on and off inside the user application:

/* Set LED intensity .. acceptable values are 0 (off) or 1, 2, and 3 */

vSys_LedIntensity( 3 );

…

/* To turn the LED on at currently set intensity */

GPIO_LED = 1;

…

/* To turn the LED off, keep the intensity setting */

GPIO_LED = 0;