ColdFire/68K Microcontrollers and ProcessorsのトピックAtomic Read/Write of SR https://community.nxp.com/t5/ColdFire-68K-Microcontrollers/Atomic-Read-Write-of-SR/m-p/179501#M7255 <HTML><HEAD></HEAD><BODY><SPAN>What is the best way to perform the following operations in an atomic manner: ?</SPAN><BR /><BR /><SPAN>- Read current value for SR[I] and retain it so that it can be restored later</SPAN><BR /><SPAN>- Set SR[I] to some specified value</SPAN><BR /><BR /><SPAN>Note that I do not wish to change any of the SR bits other than those associated with SR[I].</SPAN><BR /><BR /><SPAN>I am hoping that there is an easier way to do this than to:</SPAN><BR /><SPAN>- Call STRLDSR with a value of 0x2700 (thus disabling interrupts)</SPAN><BR /><SPAN>- Pop the SR that STRLDSR pushed on to the stack</SPAN><BR /><SPAN>- Modify bits 8-10 of the popped value to match the desired SR[I]</SPAN><BR /><SPAN>- Set SR to the modified value</SPAN><BR /><BR /><SPAN>Thanks.</SPAN><DIV> </DIV></BODY></HTML> Tue, 12 Aug 2008 23:45:26 GMT BTaylor 2008-08-12T23:45:26Z Atomic Read/Write of SR https://community.nxp.com/t5/ColdFire-68K-Microcontrollers/Atomic-Read-Write-of-SR/m-p/179501#M7255 <HTML><HEAD></HEAD><BODY><SPAN>What is the best way to perform the following operations in an atomic manner: ?</SPAN><BR /><BR /><SPAN>- Read current value for SR[I] and retain it so that it can be restored later</SPAN><BR /><SPAN>- Set SR[I] to some specified value</SPAN><BR /><BR /><SPAN>Note that I do not wish to change any of the SR bits other than those associated with SR[I].</SPAN><BR /><BR /><SPAN>I am hoping that there is an easier way to do this than to:</SPAN><BR /><SPAN>- Call STRLDSR with a value of 0x2700 (thus disabling interrupts)</SPAN><BR /><SPAN>- Pop the SR that STRLDSR pushed on to the stack</SPAN><BR /><SPAN>- Modify bits 8-10 of the popped value to match the desired SR[I]</SPAN><BR /><SPAN>- Set SR to the modified value</SPAN><BR /><BR /><SPAN>Thanks.</SPAN><DIV> </DIV></BODY></HTML> Tue, 12 Aug 2008 23:45:26 GMT https://community.nxp.com/t5/ColdFire-68K-Microcontrollers/Atomic-Read-Write-of-SR/m-p/179501#M7255 BTaylor 2008-08-12T23:45:26Z Re: Atomic Read/Write of SR https://community.nxp.com/t5/ColdFire-68K-Microcontrollers/Atomic-Read-Write-of-SR/m-p/179502#M7256 <HTML><HEAD></HEAD><BODY><DIV></DIV>Hi,<BR /><BR />depending on the processor you use, did you have a look at the STLDSR instruction ?<BR />This instruction is only available on ISA_A+ and ISA_C instruction sets. For further information you can look into the Coldfire Programmer's Ref. Manual.<BR /><BR />HTH<BR />&nbsp;stzari<BR /><DIV></DIV></BODY></HTML> Wed, 13 Aug 2008 18:34:49 GMT https://community.nxp.com/t5/ColdFire-68K-Microcontrollers/Atomic-Read-Write-of-SR/m-p/179502#M7256 stzari 2008-08-13T18:34:49Z