>>> At least some of the SOCs include small CPUs. I'm not sure if a pure >>> DSP could run X or not? >>> >> IIUC, DSP chips can run an OS -- they have registers and an ALU. >> However, it appears that the consensus is that it is more efficient to >> have at least a small MCU to do that. > > What does MCU stand for in this context?
Micro-controller? I think he points to the fact that they can be run from the on-chip flash and on-chip ram. Whatever needs external memories falls in the category of "full" processors. >>> If there is no CPU, >> I was making a distinction between a CPU such as an x86 and a more >> simple MCU such as an ARM > > I was under the impression that ARM was a general purpose CPU like > x86, Alpha, Sparc, etc. as opposed to a DSP with a very specialized > instruction set. With ARM SoC you can say they are MCUs now. Otherwise ARM is strictly just the cpu core.. >>> how do you get data from the Ethernet port to the >>> decoding hardware? >>> >> I suppose that that would depend on the Ethernet chip but it would >> probably be onboard the decoding chip. If using a DiVinci chip [for >> example], the Ethernet interface and an ARM MCU are onboard. The ARM >> could take care of the Ethernet traffic whether or not a more powerful >> CPU was needed to run X. > > How powerful is the ARM in the DiVinci? Web page says 32 bit, MMU, up > to 300 MHz. I haven't studied the ARM arch or how it compares with others, > e.g. 300 MHz ARM ~= xxx MHz x86? Unless this thing is a lot more pathetic > than it sounds like, it should be able to run an X server. Any ARM in range of 300-600 MHz is approximately as powerful as a PDA/iPhone or other smart phone device. Get one and try out things - usually without dedicated hardware for graphics acceleration it is not worth much. >>> Is there a variety of flash card or similar device that the box could >>> write IP addresses to, then the memory gets moved to the bios card? >> If the computer has a flash card socket and the Video BIOS socket was >> flashable. This would work fine for distributing video on a network, >> but if it were the only display for the computer, you have the bootstrap >> problem again. This used to be solved by using a bootable floppy with >> DOS and a program to flash the BIOS. Do new systems have floppies? >> Well I guess that if they don't have floppies that they have a bootable >> CDROM or DVDROM drive. >> >>> And be inexpensive enough? >> The prices keep falling every day. They are (parallel) ATA, so most >> chips that I have looked already have the interface. All that is needed >> is the socket. They just look like a small HardDisk. > > No, not a SSD, some form of memory that can hold the bios firmware. > Take one, plug it into the box, the box writes the IP addresses > (and maybe the bios firmware) onto the memory, then the user > unplugs the memory from the box and plugs it into the card. Then > plug the card into the computer. Something designed for end-users > to plug-unplug without static zapping or bending pins. What about the > memory cards a lot of digital cameras use? Do those have a RAM memory > type interface (not PATA/SATA/SCSI SSD disk type interface) that > a CPU could boot from directly? And not cost too much? If so we > could use the same slot to hold the firmware on the Ethervideo box. Use just an SD/SHDC formated to multiple partitions, one of them could hold the bios image. Then the hardware on the add-on pc card will access that (provide a RAM memory type interface, maybe inserting wait cycles to host while translating the request). Or it can do a shadow copy to onboard RAM and map that portion as the BIOS. There are no card types with RAM type interface. The last one was PCMCIA. maybe CF could be use with direct addressing, but it is usually used in IDE compatibility mode - easier to handle and I suppose it has better performance. Daniel _______________________________________________ Open-hardware-ethervideo mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-hardware-ethervideo
