Posted on July 25, 2012 at 18:45Because the programming speed of SWD should be a lot faster than UART/CAN if you use a bootloader..
Really, do you have anything to prove this assertion? What if I run my USART at 460800 or 921600 baud, with a streaming protocol? I think the flash would be the bottleneck, any improvement from SWD would be fractional at best, not some order of magnitude. CAN would clearly blow given the packet size.
For JTAG/SWD you'd need to buy a lot of hardware and software, or be particularly skilled in the art. Cost per pod w/basic drivers, perhaps $1K licensed, development costs in the order of $10K. Contrast that to some USB serial ports, and cables that might run $20 a head, and software dev time about a quarter, ie 1 week vs 4 weeks. Cost savings there could be applied to replicating the test set up.
A single station could program multiple devices, would depend on how good you are at scaling your solution. Multiple devices could be programmed in parallel, a whole rack/array sequentially. Put a red/green LED on the individual test fixtures.
For manual labour, you'd want a big enough fixture that the test operator would be kept busy installing/removing devices as the tester rolled from one row to the next. Bin the failing devices for a single up retesting.
