# Automatic Programmer - UART\_DOWNLOAD

**URL:** <https://forum.amebaiot.com/t/automatic-programmer-uart-download/151>\
**Category:** Peripherals\
**Tags:** evb-bw16, rtl872xd\
**Created:** [January 17, 2021, 6:38pm UTC](https://forum.amebaiot.com/t/automatic-programmer-uart-download/151 "2021-01-17T18:38:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![chucklink](https://avatars.discourse-cdn.com/v4/letter/c/54ee81/32.png) [@chucklink](https://forum.amebaiot.com/u/chucklink)\
**Post date:** [January 17, 2021, 6:38pm UTC](https://forum.amebaiot.com/t/automatic-programmer-uart-download/151/1 "2021-01-17T18:38:37Z")

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Has anybody developed a simple programmer that works without the manual “pushbutton” intervention. I am new to the AMEBDA family. I find the mix of features plus dual band wifi appealing. I have ordered a couple of RTL8722DM IoT Development boards for our team to start development work. I have already received a few B&T BW16 modules for our prototypes. Studying the data Amebda-d Application Notes, I see there is an image download process called UART\_DOWNLOAD. Looks like the tool is complete except I am wondering if anybody has developed a simple circuit that pulls PA7 to ground followed by a RESET, then releases PA7. One thing that is also not clear is “RESET”. Can I activate “RESET” by taking “CHIP\_EN” low then returning high again. I can’t find another RESET input although the text in the Application notes refers to removing power and re-powering the board. I am looking for something a bit smoother. We can design a circuit, but I was hoping somebody else has created a simple solution already.  
Thanks in advance,  
Chuck

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**Author:** ![xidameng](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/xidameng/32/18_2.png) [@xidameng](https://forum.amebaiot.com/u/xidameng)\
**Post date:** [January 18, 2021, 3:07am UTC](https://forum.amebaiot.com/t/automatic-programmer-uart-download/151/2 "2021-01-18T03:07:16Z")

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Hi @chucklink ,

Glad to hear you like the features that Ameba D provides, please note that for hardware information, you may refer to our [Layout and schematic](https://www.amebaiot.com/en/amebad/) on the official website.

Also, manual intervation is only required when uploading image using UART, if you are comfortable with JLINK or SWD, then no manual intervention is required and such tools are already provided in the standard SDK that you have (under _ **tool** _ directory)

Hope this clear some doubts~

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**Author:** ![wyy](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@wyy](https://forum.amebaiot.com/u/wyy)\
**Post date:** [January 18, 2021, 3:16am UTC](https://forum.amebaiot.com/t/automatic-programmer-uart-download/151/3 "2021-01-18T03:16:42Z")

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Hi @chucklink

Yes, pulling CHIP\_EN low will put the RTL8722DM into reset, and releasing CHIP\_EN to high will reboot the chip.  
You can find more information about the pins in the datasheet from the website.

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**Author:** ![basteagow](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/basteagow/32/322_2.png) [@basteagow](https://forum.amebaiot.com/u/basteagow)\
**Post date:** [April 23, 2021, 9:29pm UTC](https://forum.amebaiot.com/t/automatic-programmer-uart-download/151/4 "2021-04-23T21:29:09Z")

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@chucklink FYI, if you ever want to enter UART\_DOWNLOAD mode from the firmware itself, you can [do so programmatically](https://forum.amebaiot.com/t/can-we-put-the-ic-into-uart-download-mode-via-command/42/3).