Generating PORT Address for I/O Microprocessor and Interfacing by Ravinder Nath Rajotiya - October 12, 2021October 12, 20210 Generating the Ports for interfacing There are two techniques or methods for interfacing i/o devices, these are: i/o-Mapped I/O- In this method, the i/o device have separate address space and instructions exclusively for inputting or outputting the data from/to the devices. Instructions for reading/writing memory are different than i/o instructions.IN and OUT are used for i/o devices, and MOV is used for memory related operations. memory-mapped I/O- This techniques uses the common address space and instructions for communicating with the memory or the i/o. MOV instruction is used for i/o as well as memory related operations. In the following paragraph we will learn how to create the port addresses for the i/o-mapped i/o technique. We will use some address decoding logic gates for
System Bus and Memory Transfer Computer Organization and Architecture by Ravinder Nath Rajotiya - March 15, 2021December 9, 20220 Bus and Memory Transfer: Introduction: as discussed in the beginning of this chapter that the micro-operation are the operations, such as the transfer, performed on the data stored in the registers. A simple system may contain few registers and the mechanism can be very simple as described below in the register transfer notation: T1 : R2 <-- R0 T3: R2 <-- R1 The two statements have a common destination but two different sources of data. Either the content of R0 or R1 is loaded in R2. Registers shown in figure are 1-bit in length (i.e. FF), however they will be of size in multiple of bytes. For this simple case we can employ a 2x1 MUX to perform the transfer operation described register=transfer notation.. Bus