Firmware Design Of SAS-SATA Bridge Controller Chip

SAS(Serial Attached SCSI(Small Computer System Interface))technology is a new generation of SCSI technology that uses serial transmission to communicate,and is also a mainstream enterprise-level storage interface.The SATA(Serial Advanced Technology Attachment)interface is a Serial ATA(Advanced Technology Attachment)interface,and its application is very extensive.With the cessation of production of SAS mechanical hard drives,enterprise-level storage is in urgent need of replacement.In order to meet the needs of enterprise-level storage,a SAS-SATA bridge chip was developed to achieve the conversion of SAS to SATA interface,so that SATA solid state drives can be recognized as SAS solid state drives.However,the chip also needs the matching firmware(chip driver)to realize its bridge(turning one storage interface into another storage interface)function.This dissertation designs and implements the corresponding firmware part of the bridge chip,and finally passes the corresponding test.First,the SAS protocol and the SATA protocol are analyzed to prepare the basic theoretical knowledge for firmware design;second,the hardware architecture of the chip is analyzed.The chip is composed of two MCU(Micro Controller Unit),SAS IP core,and SATA IP core,ACT(auto command transfer)module,Command Interface module,Mbuffer module,on-chip RAM(Random Access Memory),on-chip ROM(Read Only Memory)and SPI(Serial Peripheral Interface)module,etc.,clarifying the key technology of each module Point;Then,according to the hardware resources of the chip,design SAS and SATA firmware and its command and data transmission parts,of which MCU0(the program that is running is SAS firmware)is responsible for the scheduling between the SAS module,ACT module and Mbuffer module,MCU1(The program that is running is the SATA firmware)is responsible for the scheduling between the SATA IP core,Command Interface module and Mbuffer module;finally,burn the firmware to the bridge chip,test its corresponding bridge function and transmission rate,and discover the SAS designed in this dissertation-The SATA bridge chip firmware implements the bridge function of the chip,and the transmission rate is basically the same as the SATA solid-state transmission rate.The majority of this dissertation is focusing on SAS-SATA bridge controller's firmware design.It covers the architecture of firmware,the programming of all the subroutines(modules)and debugging.Finally,the tested results were shown in the dissertation after running the whole firmware in a real system.This firmware version had been delivered to a group for further improvement targeting to mass-production.And it did become a formal source code version for mass-production.