Altera MAX II - Manual (Page 32)

2–24 Development Kit Version 1.1.0 Altera Corporation
MAX II Development Kit Getting Started User Guide July 2005
Reference Designs
Figure 2–8. Design Overview
Linear Feedback Shift Register (LFSR)
The LFSR is a 32-bit register chain that uses combinational feedback paths
to generate pseudo-random number values. Nine taps on the 32-bit chain
are used to derive three decimal numbers that represent the value on each
reel (3 taps per reel). The LFSR is fed by a system clock, and the values of
each reel are constantly changing on the rising edge of each clock cycle.
When a player toggles the Spin button during game play, the block
captures the current value of each tap and feeds these values to the
Control block for further processing. See
Figure 2–9 .
Figure 2–9. Linear Feedback Shift Register Design
Control
This block manages the status and functionality of the player controlled
inputs Bet and Spin. The functionality of this block can be divided into
three major areas: