请教个UVM中virtual sequence的问题

IC小飞侠 · 发表于 2016-11-16 23:26:14

不太明白先mark一下

e_epsh · 发表于 2017-1-3 14:43:52

学习了，多谢分享

rainybyf · 发表于 2017-1-3 16:06:04

1，为啥里面两个seq没有执行pre_body和post_body?
因为，在start的参数里有个call_pre_post，默认值是1，表示会调用pre_body和post_body，但是在uvm_do系里的宏里面，该形参传递的是0。所以，没有被调用。
2，为啥顶层的virtual sequence的pre_body和post_body被执行了？
因为，一般情况，顶层的virtual sequence会被设置为default sequence，在start_phase_sequence时，会直接调用start，此时call_pre_post用的是默认值1，所以调用了。

RichKoala · 发表于 2017-1-8 16:05:36

回复 7# shaoqingtju

好牛，是看源码后了解的么？

mila07 · 发表于 2018-4-25 16:41:38

在sequence_library里自动选择sequence来启动的这种方式，被选择的sequence的pre_body也是没被执行的。估计是同理
学习了

iNostory · 发表于 2020-1-9 17:24:25

感谢两位的耐心解答！原来我一直走在不建议的路上...学习了，多谢！

莲心禅韵 · 发表于 2021-1-6 11:34:40

shaoqingtju 发表于 2016-9-24 15:07
回复 6# lovehere33

uvm的一种推荐用法，是在pre_body和post_body中进行raise，drop objection的操作，pr ...

REF <uvm-1.2> source code "uvm_sequence_base" class

(1) A sequence is executed by calling its <start> method,either directly or invocation of any of the `uvm_do_* macros.
(2)Executing sequences via <start>

A sequence's <start> method has ~parent_sequence~ argument that controls whether <pre_do>,<mid_do> and <post_do> are called *in the parent* sequence.It also has a ~call_pre_post~ argument that controls whether its <pre_body> and <post_body> methods are called.
默认~call_pre_post ==1 ~

(3)Excuting sub－sequences via `uvm_do macrosA sequence can also be indirectly started as a child in the <body> of a parent sequence.The child sequence's <start> method is called indirectly by invoking any of the `uvm_do macros.
In these cases, <start> is called with ~call_pre_post~ set to 0

[求助] 请教个UVM中virtual sequence的问题

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