神马文学网set_false_path
来源：百度文库 编辑：神马文学网 时间：2024/04/28 04:05:00
1. Why we want to set false path?
Just We want to tell tools don't care about these special path, andwe can make sure these defined path have no need to check or we haveother methods to check , such as dynamic simulation for asynchrouspath, or handshake function check for different clock domain.
2. Which path we should set as false path?
1). logic impossible path: we should specify these path which cannotexist in logic function, but tools cannot get enough info about theseimpossible path,especially multi master/slave bus commulation , muxselection function, memory R/W function.
2). CDC (clock domain constaint) :for these multi asynchrous clock domain, we can use handshake or FIFO to communicate.
3). test function logic path : for one real chip , we should haveenough logic for scan test or BIST test, or JTAG test, weshould seperate STA as scan test, function test, at-speed test andBIST test. So in each case, we should set different test mode enable,and set other path as false path. For example, when we do functiontest, we should set scan and BIST data path as false path .
4) other specified path by designer
Just We want to tell tools don't care about these special path, andwe can make sure these defined path have no need to check or we haveother methods to check , such as dynamic simulation for asynchrouspath, or handshake function check for different clock domain.
2. Which path we should set as false path?
1). logic impossible path: we should specify these path which cannotexist in logic function, but tools cannot get enough info about theseimpossible path,especially multi master/slave bus commulation , muxselection function, memory R/W function.
2). CDC (clock domain constaint) :for these multi asynchrous clock domain, we can use handshake or FIFO to communicate.
3). test function logic path : for one real chip , we should haveenough logic for scan test or BIST test, or JTAG test, weshould seperate STA as scan test, function test, at-speed test andBIST test. So in each case, we should set different test mode enable,and set other path as false path. For example, when we do functiontest, we should set scan and BIST data path as false path .
4) other specified path by designer