Silicon Laboratories Si4010 Software Programming Manual page 13

 Using only single interrupt priority level. The main application function can be interrupted by single ISR and any
ISR will not get interrupted any further. It also assumes that the user is compiling the ISR routine with using
directive.
2 call to ROM function
+ 8 API worst case above
+ 2 interrupt return address
+ 5 for ISR routine storage of A, DPH etc. while compiling with using 1 directive
+ 2 call to ROM function from ISR
+ 6 API worst case for function callable from ISR
+ 4 required spares
= 29 bytes
Recommended stack size is 30 + whatever the user application calling depth is.
 Using two interrupt priority levels. The main application function can be interrupted by single ISR and any ISR
can get interrupted by higher priority interrupt. It also assumes that the user is compiling the ISR routine with
using directive. The calculation assumes that the vFCast_Tune() is called either from the main application or
from ISR, but not both.
2 call to ROM function
+ 8 API worst case above
+ 2 interrupt return address
+ 5 for ISR routine storage of A, DPH etc. while compiling with using 1 directive
+ 2 call to ROM function from ISR
+ 6 API worst case for function callable from ISR
+ 2 interrupt return address
+ 5 for ISR routine storage of A, DPH etc. while compiling with using 2 directive
+ 2 call to ROM function from ISR
+ 6 API worst case for function callable from ISR
+ 4 required spares
= 44 bytes
Recommended stack size is 44 + whatever the user application calling depth is.
Rev. 1.0
AN370
13