Search found 22 matches

by mculibrk
Thu Dec 29, 2016 3:39 pm
Forum: ESP8266 SDK
Topic: ESP interrupt latency
Replies: 12
Views: 8298

Re: ESP interrupt latency

I'm really sorry for this laaaaate reply... anyway, regarding int latency... I was able to solve (kind of) the irq latency of the SPI... this was done by setting an "undocumented" (in newer versions of the header files) register of the SPI. I don't recall the exact one but I can find and p...
by mculibrk
Wed Apr 29, 2015 4:29 pm
Forum: ESP8266 SDK
Topic: ESP interrupt latency
Replies: 12
Views: 8298

Re: ESP interrupt latency

Hi there! Yeah.... I "noticed" there are a lot of "grey areas" regarding configuration "bits" of the ESP... ;) Should I send/communicate via PM/support@espressif.com or post "public" here? Anyway, I would like to have a "as constant as possible" SPI ...
by mculibrk
Mon Apr 27, 2015 10:48 am
Forum: ESP8266 HDK
Topic: Strange slow access to I/O registers
Replies: 3
Views: 3509

Re: Strange slow access to I/O registers

Thanks for the hint.... but I already tried that - with no difference. I even tried just to repeat the same write instruction (at the same offset) with identical results. I thought it could be "address/offset" related but it's not. There is no difference in just doing s32i %0, %2, 0 s32i %...
by mculibrk
Mon Apr 27, 2015 3:12 am
Forum: ESP8266 HDK
Topic: Strange slow access to I/O registers
Replies: 3
Views: 3509

Strange slow access to I/O registers

I noticed a strange behavior accessing the I/O registers of the ESP - especially SPI FIFO reigisters SPI_W0..15. I need to fill the FIFO as fast as possible so I ended up using "pure" asm to squeeze the max out of it. I'm using a "plain" RAM to FIFO copy, and the CCOUNT register ...
by mculibrk
Mon Apr 27, 2015 2:44 am
Forum: ESP8266 SDK
Topic: High priority interrupts
Replies: 0
Views: 1598

High priority interrupts

I see mentions of ESP core supporting high priority interrupts (found in RTOS SDK .h files). I would like to know how to configure them to be able to have a High prio interrupt for SPI (or other peripheral) to avoid the rather long interrupt latency (>1uS ) induced by the "shared ISR" of t...
by mculibrk
Mon Apr 27, 2015 2:39 am
Forum: ESP8266 HDK
Topic: High priority interrupts
Replies: 3
Views: 5676

High priority interrupts

I noticed the ESP core should have support for high priority interrupts (from the .h files describing the CPU found in the RTOS SDK). I would like to know how can the high priority interrupts be configured? I would like to make the SPI interrupt a high priority one, so it could have it's own interru...
by mculibrk
Mon Apr 27, 2015 1:09 am
Forum: ESP8266 SDK
Topic: Compile problem
Replies: 7
Views: 5115

Re: Compile problem

Well... at first sight could be a "data size" problem. Maybe your code is too big so some variables/functions cannot be linked in and so "missing" and generating a lot of errors. c:/espressif/xtensa-lx106-elf/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/bin/...
by mculibrk
Sun Apr 26, 2015 11:36 pm
Forum: ESP8266 SDK
Topic: ESP interrupt latency
Replies: 12
Views: 8298

Re: ESP interrupt latency

After a lot of trial/errors I can confirm the problem is/was not the Interrupt latecy alone... The thing is the SPI module "takes quite some time" to generate the interrupt... I tried a lot of options with the SPI module but nothing changes... the delay depends on the SPI CLK so a variable...
by mculibrk
Mon Apr 20, 2015 4:24 pm
Forum: ESP8266 SDK
Topic: ESP interrupt latency
Replies: 12
Views: 8298

Re: ESP interrupt latency

1.With some setting, the SPI clock may start after CS or may stop before CS. Can you catch the waveform of SPI CS for reference? I know about various settings of the CS pin/functions.... but to be honest did not think about the possible correlation... ie that the SPI CLK will be delayed for the CS ...

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