Hi all, I have two questions regarding the OPB usage. 1) why is it the microblaze connects to the IOPB port to the OPB bus when running from internal memory (BRAM) ? the program runs only from the ILMB isn't it? 2) PLB-OPB bridge , the PPC405 reference guide says that the PLB should be used for fast bus transactions and that the OPB is to be used for slower peripherals (GPIOs/UART etc.). My question is as follows - If I'm using a PLB-OPB bridge the data from/to the OPB will still go trough the PLB bus so how come it is says the the OPB usage takes some load of the PLB bus ? Thanks, Mordehay.
EDK: OPB Question
Started by ●February 14, 2006
Reply by ●February 15, 20062006-02-15
1> I have written demos where microblaze accesses the ILMB without IOPB. Where did you see this listed? Also, I have a demo with IOB without ILMB. MB just needs to have memory at start address 0x0 either on IOPB or ILMB. The ILMB is just faster since only 1 master is allowed thus no bus arbitration therefore preferred. me_2003@walla.co.il wrote:> Hi all, > I have two questions regarding the OPB usage. > 1) why is it the microblaze connects to the IOPB port to the OPB bus > when running from internal memory (BRAM) ? the program runs only from > the ILMB isn't it? > 2) PLB-OPB bridge , the PPC405 reference guide says that the PLB should > be used for fast bus transactions and that the OPB is to be used for > slower peripherals (GPIOs/UART etc.). My question is as follows - If > I'm using a PLB-OPB bridge the data > from/to the OPB will still go trough the PLB bus so how come it is says > > the the OPB usage takes some load of the PLB bus ? > Thanks, Mordehay. >