请教关于LPC2378外部总线问题？

用LPC2378接外部RAM,定义字节娈量一切正常，定义成16位或32位数则只能读到高位，不知哪里设置不对？

bjluhaijun&nbsp;，您好：<br />&nbsp;&nbsp;&nbsp;&nbsp;听您的叙述还不能知道哪里设置的不对案，但是您可以参考我们的范例程序去写，详细的内容参见Smart2300开发板配套书《ARM嵌入式系统应用笔记（上册）》中的3.20章节，这里有范例程序与讲解。<br />&nbsp;&nbsp;&nbsp;on&nbsp;duty:zlgARM_lrk

&nbsp;&nbsp;这样就可以读到正确的32位了<br />&nbsp;&nbsp;EMC_CTRL&nbsp;=&nbsp;0x00000001;<br /><br />&nbsp;&nbsp;PCONP&nbsp;&nbsp;|=&nbsp;0x00000800;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />&nbsp;&nbsp;PINSEL4&nbsp;=&nbsp;0x50000000;<br />&nbsp;&nbsp;PINSEL5&nbsp;=&nbsp;0x05050555;<br />&nbsp;&nbsp;PINSEL6&nbsp;=&nbsp;0x00005555;<br />&nbsp;&nbsp;PINSEL8&nbsp;=&nbsp;0x55555555;<br />&nbsp;&nbsp;PINSEL9&nbsp;=&nbsp;0x50090000;<br /><br />&nbsp;&nbsp;EMC_STA_CFG0&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=&nbsp;0x00000000;<br />&nbsp;&nbsp;EMC_STA_WAITWEN0&nbsp;&nbsp;=&nbsp;0x2;<br />&nbsp;&nbsp;EMC_STA_WAITOEN0&nbsp;&nbsp;=&nbsp;0x2;<br />&nbsp;&nbsp;EMC_STA_WAITRD0&nbsp;&nbsp;&nbsp;=&nbsp;0x1f;<br />&nbsp;&nbsp;EMC_STA_WAITPAGE0&nbsp;=&nbsp;0x1f;<br />&nbsp;&nbsp;EMC_STA_WAITWR0&nbsp;&nbsp;&nbsp;=&nbsp;0x1f;<br />&nbsp;&nbsp;EMC_STA_WAITTURN0&nbsp;=&nbsp;0xf;