Buriedcode
Full Member level 6
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Hi,
This is a pretty basic quesiton, but I can't seem to find a satisfactory answer, and considering its used in almost all digital comms, I thought I'd try here.
Without designing custom IC's, or using programmable logic (FPGA/CPLD) how exactly could one 'stream' bits for wireless or wired communication?
What I mean is..say we have to send: a preamble, start of frame, payload, and error check. Now, how exactly could one get this into a serial format without gaps between the data? Using a basic microcontroller (which isn't fast enough for my app, just an example) the only way to do this would be to use 'bit banging' entirely in software. A USART would either add start and stop bits between bytes, or leave a gap (as would back to back SPI).
So, do all these ASIC's for USB/ethernet/wifi simply have a shiftregister to output these bits or is there some standard I'm not aware of? where one can load in a byte or 2 and it would send it serially.
As I said, really basic question, but I haven't found much information on it, as few datasheets (or standard protocols) go into this sort of detail with the 'phy' layer. I've already asked in the microcontroller forum, but most micro users want low-bandwidth links that UART's can cope with, I would like to be able to design a fairly simple proprietary protocol from the ground up without the need for custom IC's or expensive programmable logic.
Hope someone can help,
BuriedCode.
This is a pretty basic quesiton, but I can't seem to find a satisfactory answer, and considering its used in almost all digital comms, I thought I'd try here.
Without designing custom IC's, or using programmable logic (FPGA/CPLD) how exactly could one 'stream' bits for wireless or wired communication?
What I mean is..say we have to send: a preamble, start of frame, payload, and error check. Now, how exactly could one get this into a serial format without gaps between the data? Using a basic microcontroller (which isn't fast enough for my app, just an example) the only way to do this would be to use 'bit banging' entirely in software. A USART would either add start and stop bits between bytes, or leave a gap (as would back to back SPI).
So, do all these ASIC's for USB/ethernet/wifi simply have a shiftregister to output these bits or is there some standard I'm not aware of? where one can load in a byte or 2 and it would send it serially.
As I said, really basic question, but I haven't found much information on it, as few datasheets (or standard protocols) go into this sort of detail with the 'phy' layer. I've already asked in the microcontroller forum, but most micro users want low-bandwidth links that UART's can cope with, I would like to be able to design a fairly simple proprietary protocol from the ground up without the need for custom IC's or expensive programmable logic.
Hope someone can help,
BuriedCode.