Sigma DE2-70 manual Schematic diagram of the pushbutton and toggle switches

DE2-70 User Manual

There are also 18 toggle switches (sliders) on the DE2-70 board. These switches are not debounced, and are intended for use as level-sensitive data inputs to a circuit. Each switch is connected directly to a pin on the Cyclone II FPGA. When a switch is in the DOWN position (closest to the edge of the board) it provides a low logic level (0 volts) to the FPGA, and when the switch is in the UP position it provides a high logic level (3.3 volts).

There are 27 user-controllable LEDs on the DE2-70 board. Eighteen red LEDs are situated above the 18 toggle switches, and eight green LEDs are found above the pushbutton switches (the 9th green LED is in the middle of the 7-segment displays). Each LED is driven directly by a pin on the Cyclone II FPGA; driving its associated pin to a high logic level turns the LED on, and driving the pin low turns it off. A schematic diagram that shows the pushbutton and toggle switches is given in Figure 5.4. A schematic diagram that shows the LED circuitry appears in Figure 5.5.

A list of the pin names on the Cyclone II FPGA that are connected to the toggle switches is given in Table 5.1. Similarly, the pins used to connect to the pushbutton switches and LEDs are displayed in Tables 5.2 and 5.3, respectively.

				RN33		100K
				1		8	VCC33
				2		7
				3		6
				4		5											U8
																		GND	10
																			19
																		OE
													KEYIN0		9		A8	B8	11	RN34		120	KEY0
															8				12	8		1
																	A7	B7
													KEYIN1		7				13	7		2	KEY1
																	A6	B6
													KEYIN2		6				14	6		3	KEY2
																	A5	B5
													KEYIN3		5				15	5		4	KEY3
BUTTON0		BUTTON1			BUTTON2			BUTTON3									A4	B4
															4				16
									C13	C14	C15		C16				A3	B3
4	3	4	3	4		3	4	3							3				17
																	A2	B2
															2				18
1	2	1	2	1		2	1	2	1u	1u	1u		1u				A1	B1
															1
TACT SW		TACT SW			TACT SW			TACT SW									DIR
												VCC33			20
																	VCC
																	74HC245
SW0	GND	SW1		GND	SW2		GND	SW3	GND	SW4		GND		SW5			GND		SW6	GND		SW7	GND
4		4				4		4			4				4				4			4
1	VCC33	1		VCC33		1	VCC33	1	VCC33		1	VCC33			1		VCC33		1	VCC33		1	VCC33
2	SW0	2		SW1		2	SW2	2	SW3		2	SW4			2		SW5		2	SW6		2	SW7
3	GND	3		GND		3	GND	3	GND		3	GND			3		GND		3	GND		3	GND
5	GND	5		GND		5	GND	5	GND		5	GND			5		GND		5	GND		5	GND
SLIDE SW		SLIDE SW			SLIDE SW			SLIDE SW		SLIDE SW				SLIDE SW					SLIDE SW			SLIDE SW
SW8	GND	SW9		GND	SW10		GND	SW11	GND	SW12		GND		SW13			GND
4		4				4		4			4				4
1	VCC33	1		VCC33		1	VCC33	1	VCC33		1	VCC33			1		VCC33			120	SW13
2	SW8	2		SW9		2	SW10	2	SW11		2	SW12			2				R50
3	GND	3		GND		3	GND	3	GND		3	GND			3		GND
5	GND	5		GND		5	GND	5	GND		5	GND			5		GND
SLIDE SW		SLIDE SW			SLIDE SW			SLIDE SW		SLIDE SW				SLIDE SW
SW14	GND	SW15		GND	SW16		GND	SW17	GND
4		4				4		4											KEY[0..3]
1	VCC33	1		VCC33		1	VCC33	1	VCC33				RN35	120		SW17
2	GND	2				2		2					8	1
3		3		GND		3	GND	3	GND				7	2		SW16			SW[0..17]
5	GND	5		GND		5	GND	5	GND				6	3		SW15
SLIDE SW		SLIDE SW			SLIDE SW			SLIDE SW					5	4		SW14

Figure 5.4. Schematic diagram of the pushbutton and toggle switches.

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