Need some disambiguation in 8A-GPIO document/文档8A-GPIO有表达不清楚的地方需要释疑

thuwrx10
Posts: 10
Joined: Wed Aug 19, 2015 3:59 pm

Need some disambiguation in 8A-GPIO document/文档8A-GPIO有表达不清楚的地方需要释疑

Postby thuwrx10 » Sat Aug 29, 2015 12:47 pm

It is said in 2.2.4. Output low level register GPIO_OUT_W1TC in document 8A that, if the related bit is set to be 1, the IO output is low level (at the same time, users should enable the output).
I wander what does "user should enable the output" mean? Does it mean that the user should keep in mind that output should be enabled first, or does it mean that the user must set the corresponding bit in GPIO_ENABLE register simultaneously every time when writing to GPIO_OUT_W1TC, otherwise the value in GPIO_OUT_W1TC won't have effect on register GPIO_OUT or whatever?

8A-GPIO接口文档的2.2.4节“输出低电平寄存器GPIO_OUTPUT_W1TC”说“若对应的位被置1,表示示该IO的输出为低电平(同时需要使能输出)”。这个“同时需要使能输出”是什么意思?是让开发者记得先使能输出再使用这个寄存器,还是每次写GPIO_OUTPUT_W1TC的同时都需要把GPIO_ENABLE里的对应位置1,不然GPIO_OUTPUT_W1TC寄存器里的数对GPIO_OUTPUT寄存器没有效果?

eriksl
Posts: 157
Joined: Fri May 22, 2015 6:22 pm

Re: Need some disambiguation in 8A-GPIO document/文档8A-GPIO有表达不清楚的地方需要释疑

Postby eriksl » Sun Sep 13, 2015 4:19 pm

What are you trying to accomplish?

I think we're not supposed to set registers directly at all, so I guess you won't get an answer to that.

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