东南大学 计算结构 课程设计 POC设计报告.pdf

The Design Report of the parallel output controller (POC) Computer Organization and Architecture Course Design The Report of the parallel output controller (POC) School of Information Science and Engineering Southeast University 2014 COA-POC Southeast University The Design Report of the parallel output controller (POC) 1. Purpose The purpose of this project is to design and simulate a parallel output controller (POC) which acts an interface between system bus and printer. The Altera’s Maxplus II EDA tool is recommended and provided for simulation. 2. Introduction and requirements  Basic introduction POC is one of the most common I/O modules, namely the parallel output controller. It plays the role of an interface between the computer system bus and the peripheral (such as a printer or other output devices).  Architectural Model Figure 1 Printer Connection Figure 1 shows the connecting of a printer to the system bus through the POC. The communication between POC and the printer is controlled by a “handshake” protocol illustrated in Figure 2. COA-POC Southeast University The Design Report of the parallel output controller (POC) Figure 2 The handshake-timing diagram between POC and the printer The handshaking process is described as follows: When the printer is ready to receive a character, it holds RDY=1.The POC must then hold a character at PD (parallel data)port and produce a pulse at the terminal TR (transfer request). The printer will change RDY to 0, take the character at PD and hold the RDY at 0 until the character has been printed (e.g. 5 or 10ms), then set RDY=1 again when it is ready to receive the next charac