intel. 8255A/8255A-5 CONTROL WORD INTE flip-flop definition: (BIT-SET)-INTE is set-Interrupt enable (BIT-RESET)-INTE is RESET-Interrupt disable aocalo mode selec RCTIVEEFAG Operating Modes 231308-B MODE 0(Basic Input/Output).This functional con- Figure 7.Bit Set/Reset Format psoeasmpywmen10cr7a8h6h9g 3 ports. ModeBasic Functional Defintions .Two 8-bit ports and two 4-bit port Interrupt Control Functions Any port can be input or output Outputs are latched When the 8255A is programmed to operate in mode puts are not latched 38giofnth8agouputconiguraionsarepos- MODE O(BASIC INPUT) RO 231308-9 3105 www.chipdocs.com Be sure to visit ChipDocs web site for more information
intel. 8255A/8255A-5 MODE 0(BASIC OUTPUT) 231308-10 MODE O PORT DEFINITION A Group A Group B 0, D3 00 PortA ortC Port B PortC (Upper) (Lower) 0 0 0 0 OUTPUT OUTPUT 0 OUTPUT OUTPUT 0 0 0 OUTPUT OUTPUT OUTPUT INPUT 0 0 0 OUTPUT OUTPUT 2 INPUT OUTPUT 0 0 OUTPUT OUTPUT 3 INPUT NPUT 0 1 0 0 OUTPUT INPUT 4 OUTPUT OUTPUT 0 OUTPUT INPUT 5 OUTPUT INPUT 0 OUTPUT INPUT 6 INPUT OUTPUT 0 OUTPUT INPUT 7 INPUT INPUT 0 INPUT OUTPUT 8 OUTPUT OUTPUT 1 0 0 INPUT OUTPUT 9 OUTPUT INPUT 0 INPUT OUTPUT 10 INPUT OUTPUT 1 0 INPUT OUTPUT 11 INPUT INPUT 0 0 INPUT INPUT 12 OUTPUT OUTPUT 0 INPUT INPUT 13 OUTPUT INPUT 0 INPUT INPUT 14 INPUT OUTPUT INPUT INPUT 15 INPUT INPUT 3-106 www.chipdocs.com Be sure to visit ChipDocs web site or more information
intel. 8255A/8255A-5 MODE CONFIGURATIONS 0404g020 。a 1oo o oo -D。 PC PC 231308-11 231308-12 品的 品的 3 PB,PB 231308-13 231308-14 TROL WORD 4 品品品品 品时 PAy PA PA,-PA PC,PC 231308-1 3107 www.chipdocs.com esure to visit ChipDocs web site or more