Here is a general view of the “workstation” configuration on the Xilinx SP605 board.

Notes:

• LANCE (Ethernet) and ESP (SCSI disk) are DMA peripherals which can write into the main memory. These devices are not cache-coherent.

• The IOMMU block remaps DMA accesses. On the actual computers, the Ethernet and SCSI interfaces were based on old controllers designed for 16bits CPUs, unable to address the whole RAM area. The IOMMU shuffles 4kB pages, like the CPU’s MMU.

• There are 4 asynchronous serial ports in the Sun4m architecture:

  • 1:Keyboard

  • 2:Mouse

  • 3:First serial port. Console.

  • 4:Second serial port. Unavailable.

The keyboard and mouse interfaces will come later (soon!), the serial console is currently the principal communication mean (with the Ethernet port).