This question is about the MK60FN1M0VLQ12 MCU: I feed mine with an external 24 MHz oscillator and clock settings are as follows: Core Clock = 96 MHz, Bus Clock = 48 MHz, Flash Clock = 24 MHz. No external memories are used, all code is executed from the Flash.
Shortly speaking I would like to be able to get some ideas about the program execution time under these conditions.
The reason for this is that I am using an external NAND Flash Array, interfaced via the MCU's NAND Flash controller... but as I can have up to 8 NAND Flash chips in my array, I use GPIO signals as chip selects.
Setting the GPIO pins to the desired state takes 3 assembly instructions, e.g.:
ldr r3, [pc,#56] ; 2 clock cycles execution time
mov.w r2, #256 ; 1 clock cycle
str r2, [r3, #44] ; 2 clock cyles
well, the very first question here is which clock we are talking about ? Is it the Core Clock ? ... probably ... on the other hand if it is the Core Clock, what is the meaning of the Flash Clock ? And finally the real question: how much time the execution of these three instructions will take, if all the code is in the Flash ? More generally, how can I estimate the program execution time of this MCU under these conditions ? Is there any document describing the timing ?
( I understand that with pipelines and caches it is not obvious to estimate the exact execution time... which I hope is that there is a way to - relatively easily - determine a minimum / maximum range... in fact, behind my GPIO pins there is an address decoding circuit, and I would like to know which is the maximum propagation delay for this decoding stuff for that the coming operation targeting a NAND Flash chip would not come too early, when the Chip Select signal is not yet active. )
Thanks in advance