We have a new board we are bringing up, and it keeps resetting itself. The reset behavior is somewhat board dependent, but all boards are resetting themselves, as best we can tell by asserting the nRESPWRON signal. While the nRESPWRON signal is not asserted all the voltages seem good.
One board typically would assert nRESPWRON when it jumped to U-Boot from X-Loader, or from U-Boot to Linux, or part way through decompressing Linux. At power up this board would reset itself each time it tried to begin executing U-Boot. Over about a minute it would start into executing U-Boot, and eventually completely run U-Boot without resetting. In other words, it got more stable the longer it was turned on. After a while it seemed fairly stable and we could do some U-Boot testing, and NAND writing, etc.
Another board keeps asserting nRESPWRON about every 100 ms. We can't program X-Loader or U-Boot to this board because of the resets.
Another board seems to assert nRESWARM every 7ms for about 800ms, then it stops for 500ms, then starts again with the 7ms nRESWARM assertions. When we try to download U-Boot to it over UART3 the nRESWARM resets stop while downloading, but at the end of the download process nRESPWRON is asserted and we fail to execute the just-downloaded U-Boot.
Any suggestions as to what might be causing the TPS65950 to assert nRESPWRON?
Any suggestions as to what might be causing nRESWARM to be asserted with that strange pattern?
Thanks in advance,
Chris
