https://www.pjrc.com/teensy/pins.html
This appears to apply to the AVR chips. Is there anything comparable for the ARM chips? For the AVR chips, there's information mapping each pin to bits of port registers, and I don't see anything parallel to that. (Relevant if, for some reason, I wanted to set multiple pins at once in parallel.) I've seen some references to "digitalWriteFast()", and that looks like it's extremely fast for single pin changes.
But for instance, I have an LED controller that is using six pins at a time. With AVR, you make sure those six pins are consecutive pins in a single port, and you have a single operation that sets all six pins. So, 1 cycle = 6 pins set/cleared. With the ARM chips, I'm not seeing a way to do that, and even if I can compile each operation to a single cycle, that's now six cycles minimum, so it's not even faster unless I'm overclocked...
This thread:
https://forum.pjrc.com/threads/23431-Teensy-3-using-IO-pins
Suggests that there's set/clear registers, which would allow writing to multiple pins at once, but I don't see any charts or pinouts that indicate which pins are which?
This appears to apply to the AVR chips. Is there anything comparable for the ARM chips? For the AVR chips, there's information mapping each pin to bits of port registers, and I don't see anything parallel to that. (Relevant if, for some reason, I wanted to set multiple pins at once in parallel.) I've seen some references to "digitalWriteFast()", and that looks like it's extremely fast for single pin changes.
But for instance, I have an LED controller that is using six pins at a time. With AVR, you make sure those six pins are consecutive pins in a single port, and you have a single operation that sets all six pins. So, 1 cycle = 6 pins set/cleared. With the ARM chips, I'm not seeing a way to do that, and even if I can compile each operation to a single cycle, that's now six cycles minimum, so it's not even faster unless I'm overclocked...
This thread:
https://forum.pjrc.com/threads/23431-Teensy-3-using-IO-pins
Suggests that there's set/clear registers, which would allow writing to multiple pins at once, but I don't see any charts or pinouts that indicate which pins are which?