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(https://reference.digilentinc.com/_detail/reference/programmable-logic/nexys-a7/n4l.png?id=reference%3Aprogrammable-logic%3Anexys-
a7%3Areference-manual) Figure 7.3.1 Mouse Data Format
The microcontroller also supports Microsoft® IntelliMouse®-type extensions for reporting back a third axis representing the mouse wheel,
as shown in Table 7.3.1.
Table 7.3.1. Microsoft IntelliMouse-Type Extensions, Commands, and Actions.
Command Action
EA Set stream mode. The mouse responds with “acknowledge” (0xFA) then resets its movement counters and enters stream
mode.
F4 Enable data reporting. The mouse responds with “acknowledge” (0xFA) then enables data reporting and resets its
movement counters. This command only affects behavior in stream mode. Once issued, mouse movement will
automatically generate a data packet.
F5 Disable data reporting. The mouse responds with “acknowledge” (0xFA) then disables data reporting and resets its
movement counters.
F3 Set mouse sample rate. The mouse responds with “acknowledge” (0xFA) then reads one more byte from the host. This
byte is then saved as the new sample rate, and a new “acknowledge” packet is issued.
FE Resend. FE directs mouse to re-send last packet.
FF Reset. The mouse responds with “acknowledge” (0xFA) then enters reset mode.
The Nexys A7 board uses 14 FPGA signals to create a VGA port with 4 bits-per-color and the two standard sync signals (HS – Horizontal
Sync, and VS – Vertical Sync). The color signals use resistor-divider circuits that work in conjunction with the 75-ohm termination
resistance of the VGA display to create 16 signal levels each on the red, green, and blue VGA signals. This circuit, shown in Figure 8.1,
produces video color signals that proceed in equal increments between 0V (fully off) and 0.7V (fully on). Using this circuit, 4096 different
colors can be displayed, one for each unique 12-bit pattern. A video controller circuit must be created in the FPGA to drive the sync and
color signals with the correct timing in order to produce a working display system.
8 VGA Port
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