Support Forum - the last post was truncated for some reason - this is a repost

In the code we are calling printf and have updated putchar to take each character and transfer it to an array. We have placed a port hi low transition in putchar to see how fast printf calls this code - the execution time

A simple test was run
printf("testing 123");

Printf is calling putchar at a rate of 150us per character. Executing the above printf line requires over 2ms. This has nothing to do with the data transmit from the serial port - this is just a function of printf

printing a string of 10 characters to an array should not require 2ms

Any suggestions or thoughts as to why this is slow

(Also)
The ST7/STM8 manual says printf is smart enough to know what library to compile in based on what is being printed. Ex: If I print "HI" a simple library is compiled in. Do I understand the manual correctly or do I need to do anything to ensure I am not calling a printf library that supports floating points which is not required.