The Design And Implementation Of Custom For Low-delay Register

IC still develops rapidly in accordance with Moore’s Law, there has been billionsof integrated transistors in a single chip, and the frequency of chip has sped up aboveGHz. At present, the main method of chip design is based on the semi-custom standardcell library which is in the pursuit of reliability and versatility at the expense of someperformance. Therefore, when we design high-performance processor, the standard celllibrary can not meet the speed requirements. In the40nm process, the general lvtregister delay is about60ps, the register delay has been above12%of the time delaybetween the stacks for the frequency of microprocessor beyond2GHz, reducing theregister delay can improve microprocessor performance effectively.This paper implements a kind of low-delay pulse register (LDPR，Low Delay PulseRegister) which uses the pulse latch structure can save one level of latch’s delay. In thecase of the fine-tune structure and transistor size, the register propagation delay hasreduced greatly. At the same time, the group of LDPR registers and a variety of drivecapabilities are completed, and their layouts have been finished finally. In addition, thepaper gives the application method of custom registers in the semi-custom process,combining with the use of the useful of skew can effectively reduce the delay betweenthe stacks. The layout simulation results show that, compared with the master-slaveedge flip-flops in standard cell library, the propagation delay of the implementedlow-latency pulse register has dropped50%approximately. The clock skew of theregister within the group register is so small that it can be negligible.Registers characterized can be identified and used by mainstream placement androuting tools, low delay pulse registers, this paper has proposed, will be taken as anexample of the physical design. I have written the script according to the actualengineering problems, which can make the tools use such low delay registers well.Registers applied well in the whole design process without any mistakes. To sum up,above experiments show that the proposed LDPR registers have practical value.