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kendryte / k230_docs

Kendryte K230 SDK Docs
BSD 2-Clause "Simplified" License
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[Improvement]: k230_datasheet abbreviations #21

Open yf13 opened 10 months ago

yf13 commented 10 months ago

Improvement

Can you please consider to explain the abbreviations used in k230_datasheet.md file?

For example, I am having difficullties to understand the following ones:

wangjianxin-canaan commented 9 months ago

PMU in section 1.2.14. what P stands for here? How is it related to the PWR component listed in 1.2.6 --PMU：power manager unit低功耗控制，P - power
STC in section 1.2.6. What are STC for? ---System Time Counter 系统时间计数器 What is CRP in SYSCTL part of the block diagram in section 1.3? Which one in section 1.2.6 is related to it? CRP- C:clock R:reset P:power PMU的P是chip的低功耗控制，CRP中的P是SOC内部电源域

yf13 commented 9 months ago

@wangjianxin-canaan thanks.

As CPU0 and CPU1 have independent CLICs, I am wondering how can we get single source of time? are there APIs for both RTT and Linux to get time from the same reference timer?

Also I noticed that CSI data can be time stamped, are there any more details about it? For example, are the stamps mark the shooting time of each frame or just the CSI data receiving time?

zhangxiaojingCAN commented 8 months ago

As you mentioned CPU0 and CPU1 have independent CLICs, so they have their own time. Regarding CSI data, we have hardware timestamp funtion. There're free running timers in SYSCTL, media modules like CSI or VO or Audio I/O can trigger/capture timestamp on same free running timer, called STC, system time counter. There're severl group time registers (total 64bit time value in two separate 32-bit registers. each module has two set of registers, new and old time. In each capture, current STC time will be stored in new time resiger, and original value of new will be stransfered to old time register in case SW read time may be late sometime) for each media module. In CSI, the VI hardware will trigger STC when receives one frame, then the time will be captured in the time register of VI. Software can read the time register to know when the frame is captured.

zhangxiaojingCAN commented 8 months ago

We're planning to open more detailed TRM document. It may come in several weeks.