Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

User avatar
By RFZ
#68742 Hi,
since I was using some register manipulation lately (sending data via SPI and UART by directly manipulating registers) I was really surprised that I couldn't find any documentation at all about the registers...
Is it just me being blind, or isn't there any documentation?

The only documentation I found is https://github.com/esp8266/esp8266-wiki ... -registers which is a copy of viewtopic.php?f=13&t=273, both being three years old and only talking about GPIOs.
Since I also found that I can simply use GPOS / GPOC for setting / clearing bits, I also think this documentation is outdated.

For SPI and UART I haven't found anything about the registers like SPI1U / SPI1U1 / SPI1CMD / U1D / U1S / ... except their definition in https://github.com/esp8266/Arduino/blob ... 266_peri.h for the Arduino IDE.
By looking at the comments of this file and reverse engineering some higher level spi/uart functions of the Arduino SDK I was able to find the necessary information about the registers... But that was pretty time consuming.

Is there any attempt of documenting these registers I may have missed?
User avatar
By RFZ
#68759 Well, but then, why is there Information about the GPIO registers in the Wiki of this page and also a (blank) page for JTAG? I would really appreciate any documentation of these registers in the wiki. Why not?
For sure, I'm willing to contribute to the wiki too, but my problem is that I am really the wrong person for this. I've just started playing around with the ESP and the Arduino IDE... not even the basic espressif SDK. There are lots of people out there who know way more about the registers than I do... (I don't even know if the register definitions / names I used still apply if you just use the espressif SDK, not the Arduino IDE)
I don't feel confident enough to actually start a new section in the wiki about hardware registers :|
Any volunteers? :roll:
User avatar
By Barnabybear
#68764 Hi, there is some usefull stuff on this site but you have to click the links and hope unless you speak Rusian.

https://esp8266.ru/

A couple I bookmarked:
https://esp8266.ru/esp8266-gpio-register/
https://esp8266.ru/esp8266-uart-reg/
https://esp8266.ru/esp8266-pin-register-strapping/