Texas Instruments EK-LM4F232, Руководство пользователя, Страница: 10 / 22

Example Applications
2.9 Interrupts (interrupts)
This example application demonstrates the interrupt preemption and tail-chaining capabilities of
Cortex-M4 microprocessor and NVIC. Nested interrupts are synthesized when the interrupts have
the same priority, increasing priorities, and decreasing priorities. With increasing priorities, pre-
emption will occur; in the other two cases tail-chaining will occur. The currently pending interrupts
and the currently executing interrupt will be displayed on the display; GPIO pins D0, D1 and D2 will
be asserted upon interrupt handler entry and de-asserted before interrupt handler exit so that the
off-to-on time can be observed with a scope or logic analyzer to see the speed of tail-chaining (for
the two cases where tail-chaining is occurring).
2.10 MPU (mpu_fault)
This example application demonstrates the use of the MPU to protect a region of memory from
access, and to generate a memory management fault when there is an access violation.
2.11 Data Logger (qs-logger)
This example application is a data logger. It can be configured to collect data from up to 10 data
sources. The possible data sources are:
4 analog inputs, 0-20V
3-axis accelerometer
internal and external temperature sensors
processor current consumption
The data logger provides a menu navigation that is operated by the buttons on the EK-LM4F232
board (up, down, left, right, select). The data logger can be configured by using the menus. The
following items can be configured:
data sources to be logged
sample rate
storage location
sleep modes
clock
Using the data logger:
Use the CONFIG menu to configure the data logger. The following choices are provided:
CHANNELS - enable specific channels of data that will be logged
PERIOD - select the sample period
STORAGE - select where the collected data will be stored:
• FLASH - stored in the internal flash memory
• USB - stored on a connected USB memory stick
10 February 22, 2017