We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 17216

3.2 EDK MicroBlaze - How do I read the Machie Status Register (MSR) in MicroBlaze?


General Description: 

How do I read the Machie Status Register (MSR) in MicroBlaze?


To read the MSR, use the mfs (move from special) assembly instruction, and insert the assembly instruction in your C code as follows: 


int k; 

asm ("mfs %0, rmsr" : "=d" (k)); 


The above instruction transfers the contents of the MSR into the "k" variable. Alternatively, if you know which register you want to read the MSR into, you can directly specify it. 


When moving the contents to the variable, beware that the compiler may move the instruction around since it is not dependent on any inputs. To avoid this issue, you can supply a dependency in the asm instruction as follows: 

int k; 

a = b*c; 

asm ("mfs %0, rmsr" : "=d" (k) : "d" (a));

AR# 17216
Date 05/15/2014
Status Archive
Type General Article
Page Bookmarked