keypad_emu Entity Reference

Emulates PMOD keypad. More...

Detailed Description

Emulates PMOD keypad.

Propagates inputs from keypad_columns into keypad_rows, according to the bits of pressed_keys, which is a vector that has 1 bit for each key in the keypad. Please read the detailed description of the architecture to understand which bit of the vector maps to each key.

Definition at line 20 of file keypad_emu.vhd.

Entities
keypad_emu_arch	architecture
	Architecture is based on multiple concurrent assignments to the same signal, but some of the drivers are weak (pullups), just like the real hardware. More...

Libraries
ieee
	Use IEEE standard definitions library.

Use Clauses
std_logic_1164
	Use std_logic* signal types.
vhdl_verification	Package <vhdl_verification>
	Use the slv2string function.

Generics
VERBOSE	boolean := false
	If true, log changes in the pressed_keys vector, apart from the changes in the individual keys. Also log which row is connected to which column when a key is pressed.

Ports
keypad_rows	out std_logic_vector ( 3 downto 0 )
	This is the signal that must be read from the keypad.
keypad_columns	in std_logic_vector ( 3 downto 0 )
	Connect here the signal that drives the keypad.
pressed_keys	in std_logic_vector ( 15 downto 0 )
	One bit for each key. Set to '1' to emulate key press, set to '0' to emulate key release.

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The documentation for this class was generated from the following file:

• src/keypad_emu.vhd