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winIDEA Help

Version: 9.21.150

Special Function Registers

winIDEA provides a specialized window (SFR window) to display CPU's On-Chip special function registers.


SFR Window allows you to:




By default the SFR Window is populated with the SFRs based on the CPU you are debugging. If a different set of SFRs is required, you can override this selection.



Opening Special Function Registers

Select View menu / Debug / Special Function Registers or press Special Function Registers SFRWindowButton button in the main toolbar to open it.




A register corresponds to a CPU's special function register. Along with the name, its address and current value are displayed. Where a special function register contains fields of bits, it can be expanded to show sub-registers.



SFR Display pane

  • Name - Names of the (sub-)groups or (sub-)registers
  • Value - Displays values and names of the register (if selected in the 'sub-register display' of the context menu)


If the value can not be read, appropriate message is displayed. In case that reading of this SFR was skipped due to refresh abort, skipped is written instead of the value. You can disable refresh aborts in the SFR Options.

To modify register value, double click on its value and enter the new value. Whenever possible, sub-registers are modified without writing the entire register (bit addressable registers). If a sub-register can not be accessed independently of its register, the register is first read, sub-register bits are adjusted, and the whole register is written back.

  • Address - Displays address of the SFRs, as well as bit position (O) and size (S) for the sub-registers.
  • Description - Displays a description of the peripheral group, register or a field (if it is available in the SFR specification file).



Context menu

Right-clicking within SFR opens context menu.





Sub-register display - Display/Hide sub-registers in values/names and values

Edit value - Enter (if available) new value

Copy - Copies the contents of the underlying cell to the clipboard

Display Mode - Switch between binary, hexadecimal, decimal and character display

Create Initialization Script - All selected SFRs which can be read and written are exported to a Python file along with their current values

Show Filter - Show/hide filter above in the display pane of the SFR Window.

Real time update -  If you wish to monitor SFRs in the real-time enable this option.


Find - Search SFRs by name or address

Properties -  Shows Name, Address, Size (bits), Offset (bits), Access, Value of selected register

Save - Save SFR content.


Auto Fit - Adjusts the width of columns to fit the content into the available space

Options - Customize display, colors and fonts of the SFR Window.




To display or hide columns right-click on a column header and select what you want to see.



SFRs Database

Refer to Tools menu / Option / SFRs.



SFR Options

To configure the window options right-click in the window and select Options from the context menu.


Options dialog allows you to display information for easier navigation:




More resources


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