Modular Router Interface Design

This paper gives a brief introduction about traditional routers, discusses their flaws and points out that modularization is the trend of the development of routers. Then we illustrate the reasons why we choose MPC860T as the CPU of modularized router.We divide the whole design into three parts based on the characters of MPC860T: the main board design, the self-define slot design and the communication board design.In the main board design we emphasize the function blocks which are tightly related to the modularized router interface, so we give the description of those function blocks design such as CPU block design, reset block design, clock block design, debug block design and memory block design. In the part of self-define slot design, we firstly expatiate the SCCs of MPC860T because of their importance of self-define slot design,then we compelete the slot based on the requirements of communication boards.At last we give a description of how CPU can identify the slot and the communication boards in the slot.In the part of communication board design ,we foucs on E1 communication board because of its importance in the telecommunication .We compare the connection and the time-squence between the pins of E1 interface chip and the ones of self-define slot, and then introduce the software implementation based on QMC protocol. At last,we describe the transformation between V.35 signal and E1Signal.