Reset Push Buttons - ARM MPS2 Technical Reference Manual

3.5

Reset push buttons

The MPS2 and MPS2+ FPGA Prototyping Boards provide two push buttons which initiate reset and
configuration. The two reset push buttons are the ON/OFF/Soft RESET and the Hardware RESET
buttons. This section describes the use and functions of these push buttons.
This section contains the following subsections:
• 3.5.1 ON/OFF/Soft RESET button on page
• 3.5.2 Hardware RESET button on page
3.5.1 ON/OFF/Soft RESET button
The MPS2 and MPS2+ FPGA Prototyping Boards provide an ON/OFF/Soft RESET push button that
enables you to perform a software reset of the system.
You initiate a software reset of the system by briefly pressing the ON/OFF/Soft RESET button during
runtime. The MCC performs a software reset of the FPGA and resets the devices on the board. It does
not perform a full reconfiguration of the FPGA.
The software reset sequence is as follows:
1. You briefly press the ON/OFF/Soft RESET button.
If you press and hold the ON/OFF/Soft RESET button for more than two seconds, the system enters
the standby state in the same way as pressing the Hardware RESET button.
2. The MCC asserts the nRST reset signal. It might also assert nPOR but this depends on the setting of
the variable
3. The MCC releases nPOR if it is active depending on the setting of the variable
configuration file
4. The MCC releases nRST.
5. The board enters the run state.
The MCC does not read the configuration files or perform a board reconfiguration as a result of a
software reset.
Related information
1.3 Location of components on the MPS2 FPGA Prototyping Board on page 1-17
1.4 Location of components on the MPS2+ FPGA Prototyping Board on page 1-19
3.5.2 Hardware RESET button
The MPS2 and MPS2+ FPGA Prototyping Boards provide a Hardware RESET push button that enables
you to perform a hardware reset of the system.
You can change the operation of the board from ON to standby by briefly pressing this button. This
switches off the power to the board and resets the system to the default values.
If you then press the ON/OFF/Soft RESET push button, the system performs a full configuration and
enters the run state.
Related information
1.3 Location of components on the MPS2 FPGA Prototyping Board on page 1-17
1.4 Location of components on the MPS2+ FPGA Prototyping Board on page 1-19
100112_0200_09_en
Caution
in the configuration file
ASSERTNPOR
.
config.txt
Note
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rights reserved.
Non-Confidential
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.
config.txt
3 Configuration
3.5 Reset push buttons
in the
ASSERTNPOR
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