3 ms·
Some of the PCB layer diagrams look pretty cool: https://www.imx6rex.com/wp-content/uploads/2016/02/OpenRex-L8-1182px.jpg https://www.imx6rex.com/wp-content/upl
by ac29 8y ago
Some of the PCB layer diagrams look pretty cool: https://www.imx6rex.com/wp-content/uploads/2016/02/OpenRex-L8-1182px.jpg https://www.imx6rex.com/wp-content/uploads/2016/02/OpenRex-L...
Anyone know why they are designed this way? Very wiggly traces.
- nyc 8y agoTypically those wiggles are for length matching on parallel busses. Since the signals are clocked at a high speed, ensuring all the bits arrive at the same time is crucial.
- akiselev 8y agoNot just parallel buses. You can see several differential pairs as well, which look a lot like the parallel buses except the pairs are routed much closer together. Differential pairs carry polar opposite signals so that any noise can be canceled out by comparing the two. While parallel bus traces need to be routed to 1/20-1/40th of a wavelength, the differential pairs need to be routed to within 20mils of each other with impedance controlled traces (which depends on distance to each other and other traces as well as material variability, hence the tight routing).