Accessing I_O devices.html (1625B)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3 <html><head><link rel="stylesheet" href="sitewide.css" /><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><meta name="exporter-version" content="Evernote Mac 6.13.1 (455785)"/><meta name="altitude" content="-0.2330510020256042"/><meta name="author" content="Alex Balgavy"/><meta name="created" content="2017-12-17 11:57:04 AM +0000"/><meta name="latitude" content="52.37362192175261"/><meta name="longitude" content="4.836259202323236"/><meta name="source" content="desktop.mac"/><meta name="updated" content="2017-12-17 1:34:09 PM +0000"/><title>Accessing I/O devices</title></head><body><div>I/O means input/output — e.g. input from switch/microphone, output to speaker/motor/whatever</div><div><br/></div><div>components of a computer system communicate through interconnection network (circuits)</div><div>each I/O device appears to processor as addressable locations</div><div>implemented as bit storage flip-flops in the form of registers (“I/O registers”)</div><div>I/O devices and memory share same address space — “memory-mapped I/O)</div><div>this means that any instruction which accesses memory can access the device</div><div><br/></div><div><span style="font-weight: bold;">I/O device interface</span></div><div>a device is connected to interconnection network using a circuit — “device interface”</div><div>provides means for data transfer, exchange of status & control info</div><div><br/></div></body></html>