Based　on　the　step　function　and　signum　function,　a　chaotic　system　which　can　generate　multiscroll　chaotic　attractors　with　arrangement　of　saddle-shapes　is　proposed　and　the　stability　of　its　equilibrium　points　is　analyzed.　The　under　mechanism　for　the　generation　of　multiscroll　chaotic　attractors　and　the　reason　for　the　arrangement　of　saddle　shapes　and　being　symmetric　about　y-axis　are　presented,　and　the　rule　for　controlling　the　number　of　scroll　chaotic　attractors　with　saddle　shapes　is　designed.　Based　on　the　core　chips　including　Altera　Cyclone　IV　EP4CE10F17C8　Field　Programmable　Gate　Array　and　Digital　to　Analog　Converter　chip　AD9767,　the　peripheral　circuit　and　the　Verilog　Hardware　Description　Language　program　for　realization　of　the　proposed　multiscroll　chaotic　system　is　constructed　and　some　experimental　results　are　presented　for　confirmation.　The　research　result　shows　that　the　occupation　of　multipliers　and　Phase-Locked　Loops　in　Field　Programmable　Gate　Array　is　zero.　©　2020　Faqiang　Wang　and　Yufang　Xiao.