Memory locations & addresses.md (880B)
1 +++ 2 title = 'Memory locations & addresses' 3 +++ 4 # Memory locations & addresses 5 memory has storage cells, each for one bit 6 7 bits are handled in groups — words 8 9 modern word length — 32 or 64 bits 10 11 32-bit can store four ASCII characters or 32-bit signed number in one word (4 bytes) 12 13 to retrieve a single item of info, an address is used 14 15 successive addresses refer to successive byte locations in memory (byte-addressable memory) 16 17 in a 32-bit processor, words are located at addresses {0, 4, 8, …} 18 19 two ways of assignment across words: 20 21 - big-endian: lower byte addresses are used for more significant (leftmost) bytes of the word (the end bit has the biggest address) 22 - little-endian: lower byte addresses are used for less significant bytes (the end bit has the lowest address) 23 24 alignment — if words begin at byte addresses that are a multiple of the byte length of a word