8088 ya mutu a ƙarƙashin na'urar hangen nesa, tare da manyan tubalan aiki. Wannan hoton yana nuna nau'in ƙarfe ɗaya na guntu; polysilicon da silicon suna ƙarƙashin. (Credit: Ken Shirriff)
Cache prefetching shine abin da ke ba masu sarrafawa damar samun bayanai da/ko umarnin da aka shirya don amfani a cikin ma'ajiyar gida mai sauri maimakon jiran buƙatun nema don shiga cikin tsarin RAM da sake dawowa. Intel 8088 (da babban ɗan'uwansa 8086) processor yana daga cikin na'urori na farko don aiwatar da (umarni) prefetching a cikin kayan aiki, wanda [Ken Shirriff] ya yi nazari dangane da mutuwar hotuna na wannan sanannen mai sarrafawa. Wannan ya biyo baya zurfin nutsewa na bara zuwa cikin kayan aikin prefetching na 8086, tare da (ba abin mamaki ba) kamanceceniya da yawa tsakanin waɗannan microprocessors biyu, da kuma ƴan bambance-bambancen da galibi suka kasance saboda 8088's yanke-down 8-bit data bas.
Yayin da 8086 yana da 3 16-bit ramummuka a cikin umarnin prefetcher 8088 yana samun ramummuka 4, kowane 8-bit. Kayan aikin prefetching wani ɓangare ne na Unit Interface Unit (BIU), wanda ke sarrafa ainihin na'ura mai sarrafa (Execution Unit, ko EU) daga tsarin RAM. Yayin da MPUs da suka gabata za su kasance da cikakken ƙididdigewa, tare da umarni ana ɗora su daga RAM kuma daga baya ana aiwatar da su, 8086 da 8088's prefetching yana nufin cewa irin wannan zato ba gaskiya bane. Ƙarin fasalulluka a cikin BIU kuma yana nufin cewa alamar koyarwa (IP) da rajista masu alaƙa sun koma BIU, yayin da ma'anar ringbuffer a kusa da jerin gwano dole ne ta ko ta yaya ta ci gaba da yin layi da masu nuni a cikin RAM suna aiki daidai.
Ko da yake a kwanakin nan CPUs sun fi rikitarwa, cache-mataki da yawa waɗanda aka auna su a kilobytes da megabyte, yana da ban sha'awa ganin inda duk ya fara, tare da ƴan bytes kawai da ingantattun dabaru na kayan masarufi waɗanda zaka iya bi a ƙarƙashin na'urar hangen nesa. .
