Posted on March 19, 2014 at 12:41In some peripheral some API is needed,for example API functions for read and write to a GPIO port is needed(write/read to/from all pins at one operation).
another example in usart API functions, that for receiver we need a function that can get a given number of bytes and return on timeout if no further bytes is received for a give timeout.
for write protocols like as modbus RTU slave this is needed,we can get predefined number of bytes in Rx,some times number of Rx bytes in packet is not known and depends on external device response.
