Interfacing 8259 with 8085: Fig. 14.72 shows Interfacing 8259 with 8085 microprocessor system. Addressing of 8259A : The 74LS138 address decoder will assert the CS input of the 8259A when…
8259 Block Diagram: Fig. 14.71 shows the internal 8259 Block Diagram. It includes eight blocks : data bus buffer, read/write logic, control logic, three registers (IRR, ISR and IMR), priority…
Features of 8259 Programmable Interrupt Controller: The Features of 8259 Programmable Interrupt Controller are 1. It can manage eight priority interrupts. This is equivalent to providing eight interrupt pins on the…
8257 Pin Diagram: Fig. 14.61 shows 8257 Pin Diagram. Data Bus (D0-D7) : These are bi-directional tri-state signals connected to the system data bus. When CPU is having control of…
8257 DMA Controller: In microprocessor based systems data transfer can be controlled by either software or hardware. Upto this point we have used program instructions to transfer data from I/O…
Features of 8251 Microcontroller: The features of Features of 8251 Microcontroller are namely, 1. The Intel 8251A is an universal synchronous and asynchronous communication controller. 2. It supports standard asynchronous protocol…
Serial Communication Interface 8251: Most of the microprocessors are designed for parallel communication. In parallel communication number of lines required to transfer data depend on the number of bits to…
8255 Interfacing with 8086: Fig. 14.17 shows the 8255 Interfacing with 8086 Microprocessor and Interfacing 8255 with 8085 Microprocessor in I/O mapped I/O technique. Here RD and WR signals are…