diff --git a/docs/x86/ops/UMOV/README.md b/docs/x86/ops/UMOV/README.md index 391461807..d17841cb4 100644 --- a/docs/x86/ops/UMOV/README.md +++ b/docs/x86/ops/UMOV/README.md @@ -29,6 +29,7 @@ From [http://www.rcollins.org/secrets/opcodes/UMOV.html](http://www.rcollins.org cycles. Since the '386 is a dynamic device, it must be executing some instructions during HALT, but it is not doing it in a way recognizable to a logic analyzer with a '386 probe attached. + During HALT mode, the ICE differentiates between USER space and HOST space. The ICE is fetching, and performing all bus cycles to HOST memory space during HALT, and not USER space. Since the @@ -36,8 +37,10 @@ From [http://www.rcollins.org/secrets/opcodes/UMOV.html](http://www.rcollins.org mechanism to access user memory space. That mechanism is UMOV. When a user request to view memory, or disassemble memory, the ICE executes UMOV instructions to get data from User space. + If UMOV is executed by a user program, it will appear it is a alias for MOV. + The field operands to UMOV are exactly the same as the MOV instruction. For example: d Direction. If set (d=1), do memory to register, or register