Memory locations & addresses.html (1802B)
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="-1.431357145309448"/><meta name="author" content="Alex Balgavy"/><meta name="created" content="2017-12-11 11:08:37 AM +0000"/><meta name="latitude" content="52.333249125602"/><meta name="longitude" content="4.866755076539879"/><meta name="source" content="desktop.mac"/><meta name="updated" content="2017-12-11 6:06:51 PM +0000"/><title>Memory locations & addresses</title></head><body><div>memory has storage cells, each for one bit</div><div>bits are handled in groups — words</div><div>modern word length — 32 or 64 bits</div><div>32-bit can store four ASCII characters or 32-bit signed number in one word (4 bytes)</div><div><br/></div><div>to retrieve a single item of info, an address is used</div><div>successive addresses refer to successive byte locations in memory (byte-addressable memory)</div><div>in a 32-bit processor, words are located at addresses {0, 4, 8, …}</div><div><br/></div><div>two ways of assignment across words:</div><div><ul><li>big-endian: lower byte addresses are used for more significant (leftmost) bytes of the word (the end bit has the biggest address)</li><li>little-endian: lower byte addresses are used for less significant bytes (the end bit has the lowest address)</li></ul><div><br/></div></div><div>alignment — if words begin at byte addresses that are a multiple of the byte length of a word</div><div><br/></div><div><br/></div><div><br/></div></body></html>