ex1.pnx

[VHDL经典设计26例]--在xilinx芯片上调试通过--[01--1位全加器][02--2选1多路选择器][03--8位硬件加法器][04--7段数码显示译码器][05--8位串入并出寄存器][

<?xml version='1.0' encoding='utf-8' ?>
<!DOCTYPE ibis [
<!ELEMENT ibis (part, pin+)>
<!ELEMENT part EMPTY>
<!ELEMENT pin EMPTY>
<!ATTLIST part
  arch   CDATA #REQUIRED
  device CDATA #REQUIRED
  spg    CDATA #REQUIRED
  pkg    CDATA #REQUIRED>
<!ATTLIST pin
  nm     CDATA #REQUIRED
  no     CDATA #REQUIRED
  iostd  (TTL|LVTTL|LVCMOS2|NA) "NA"
  sr     (SLOW|FAST|slow|fast) "SLOW">
]>
<ibis><part pkg="PC84" spg="-7" arch="xc9500" device="XC9572"/><pin nm="b" no="23"/><pin nm="a" no="20"/><pin nm="c_in" no="24"/><pin nm="c_out" no="52" sr="fast"/><pin nm="sum" no="56" sr="fast"/></ibis>