Inputs and displays¶

Switch¶

Switch as rendered in RGate

Pin: Z output, normally one bit. Initial value comes from Properties. During simulation click the switch to toggle 0/1. A fresh run restores its configured initial value.

Use for reset, enable, mode, and other manual controls. On active-low inputs a switch at zero asserts the control; the LC-3's RESET_N is an example.

DIP switch¶

DIP switch as rendered in RGate

Pin: Z output, configurable bus width; default eight bits. Set a decimal or 0x initial value before simulation.

During simulation click the DIP to open a hex value dialog. Enter digits such as AB or 0xAB, then Apply. The value must fit the bus, including widths above 64 bits. The simulator pauses for input entry; resume when ready. Use Properties in Edit to change the saved initial value.

Ground and Vdd¶

Component	Symbol
Ground
Vdd

Pin: Z output. Ground supplies all-zero bits; Vdd supplies all-one bits at the selected width. Use them wherever your circuit needs a digital constant.

Clock¶

Pin: Z one-bit output. Set period, phase delay, and high-duty percentage (1–99) in Properties. Period must be at least 2 ns.

The clock starts low. Its first rising edge occurs after phase + low interval. High time is period×duty/100 rounded down and clamped to at least 1 ns and at most period−1; low time is the remainder.

Example: period=100 ns, phase=10 ns, duty=25% → rising at 85 ns, falling at 110 ns, rising at 185 ns. Default duty is 50%.

Press Tab to advance one period of the fastest clock in the running hierarchy. Play advances simulation time. See simulation.

LED¶

Component	Symbol
Bit LED
Bar graph
Direct seven-segment
Hexadecimal digits
Decimal digits

Pin: I input. LEDs display the value on their input. Double-click in Edit or select/Enter to choose Display type.

Choosing LED display mode

Mode	Meaning	Recommended width
Bit LED	On/off indicator; first bit drives the lamp	1
Bar graph	One light per bit; most-significant on left	8
Hex digits	One seven-segment digit for each four bits	8 (two digits)
Decimal digits	Unsigned value, enough digits for the full width; leading zeros retained	8 (three digits)
Direct 7-segment	Seven input bits independently drive each digit's segments	7 (one digit)

Selecting a mode on an unwired LED applies the recommended width. Properties shows the resulting lights/digits. You can override width before wiring. Selecting a mode on a wired LED preserves bus width.

Direct segment map for each seven-bit group:

          bit 0
       ┌────────┐
 bit 1 │        │ bit 2
       ├────────┤  ← bit 3
 bit 4 │        │ bit 5
       └────────┘
          bit 6

The low seven bits drive the rightmost digit; additional groups appear to its left. Hex groups also start with the low nibble on the right. For an incomplete high digit, bits outside the bus are zero.

Classic on/off segments are red/pale red; X is gray and Z amber. Other themes use their palette. Floating and unknown bits are shown explicitly in the display. LEDs rotate with the component. Choose the display mode in Properties.

GPIO peripheral¶

GPIO peripheral as rendered in RGate

Pins: I input and Z output, both at configured width (default eight). Z starts at the initial value. Click during simulation to increment it modulo its width. The component shows incoming I and outgoing Z values.

Use Z to drive a circuit and I to watch a signal. Configure the initial value in Properties, then change it interactively during simulation.

For a text terminal, use TTY.