Unexpected system reset(may caused with spi and twi conflict)

[nimalhuang]

Hi, Guys,

I have occured a wired thing. I use NRF51822 with softdevice S130 to do a BLE project. I use both spi and twi to get information from sensor(I use spi0 and twi1, I know that the spi0 and twi0 share the same base address). However, after power on, the chip continuously reset itself. The reset reason is 0x08 cpu lock-up. The wired thing is, this won't happen during the debug session. only happen on regular power-on session. So I can not even debug where goes wrong. Does anyone who may know this? Thank you so much.

I use twi_hw_master and spi_master from the SDK V7.1.0, but I use SHORTS in twi_hd_master instead of PPI.

UPDATE: after tried several times, I think I know what's going on, the thing is SPI and TWI can not coexist. If I disable one of these two, the system works fine. But I still don't know why, because I use SPI0 and TWI1, there two peripheral didn't share the resource. Does any one know why?

[RK]

SPI0 and TWI1 can most definitely co-exist. I use that combination. Whatever your problem is, that's not it.

[nimalhuang]

yeah, I know, but when I disable one of these, that's worked, really wired? Do you have some suggestion?

[cnchen]

Hi,

I'm encountering exactly the same issue where TWI0 and SPI1 seem to be incompatible with each other.

The attempt of using both hardware modules above always triggers an unexpected system reset.

Did you figure out the root cause or the workaround yet?

[Wojtek]

could you set breakpoint in hardfault (or in your error handler that causes reset) and check call stack? you will see which function causes this problem.

[nimalhuang]

Hi, cnchen,

I figured out the issue. The reset issue is not caused by TWI0 and SPI1 incompatible. But due to flash storage shortage. The code size of our system is a little big. So it reach the boundary of the total 256kb flash memory. After optimize the code and decrease the code size the system works fine. I know this is really a specific case for me. I am not sure if you have the same root cause. But might be a way of solution. Just for your information. Thanks.