clock.pnx

利用xilin实验仪完成一个可以计时的数字时钟

<?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="XC95108"/><pin nm="clk" no="9"/><pin nm="keyen" no="55"/><pin nm="keyclr" no="54"/><pin nm="lddat&lt;1&gt;" no="41" sr="fast"/><pin nm="lddat&lt;4&gt;" no="45" sr="fast"/><pin nm="lddat&lt;3&gt;" no="44" sr="fast"/><pin nm="lddat&lt;5&gt;" no="46" sr="fast"/><pin nm="lddat&lt;0&gt;" no="40" sr="fast"/><pin nm="lddat&lt;2&gt;" no="43" sr="fast"/><pin nm="lddat&lt;6&gt;" no="47" sr="fast"/><pin nm="ldsel&lt;0&gt;" no="50" sr="fast"/><pin nm="ldsel&lt;1&gt;" no="51" sr="fast"/><pin nm="ldsel&lt;2&gt;" no="52" sr="fast"/><pin nm="ldsel&lt;3&gt;" no="53" sr="fast"/><pin nm="lddat&lt;7&gt;" no="48" sr="fast"/></ibis>