AnsweredAssumed Answered

i.MX 8M Mini - unable to read boundary scan

Question asked by adevries on Jan 27, 2020
Latest reply on Jan 29, 2020 by adevries



I am attempting to use boundary scanning on an i.MX 8M Mini processor, and I cannot seem to read the input states of the pins properly. I have 2 devices in my JTAG chain, with the i.MX being the first device. I'm using a JTAGLive scanner to do some boundary scanning, and it is able to discover both devices in my chain. Using the boundary scanning controller, I can toggle the outputs of both devices, and I know that I am clocking data into the chain and receiving different data being clocked out of the chain. However, whenever I try to read the input status of different pins on the i.MX, their status never changes. I have checked this with multiple pins. I am currently booting with BOOT_MODE 0 and 1 pulled high by 4.7k, TEST_MODE pulled high by 4.7k, JTAG_MOD pulled low by 100k, WDOG_B pulled high by a 10k, I believe I have everything set correctly. I can get the boundary scanning ID number, and it is shown as 00011100111110000000010101010011, which is what I expect to see based on the BSDL file. I just can't seem to read a changing input on this device.


Does anyone have any ideas what might cause this kind of boundary scanning behavior? Or has anyone successfully implemented boundary scanning on an i.MX 8M Mini?


I'm happy to provide additional information, boundary scanning results, or anything else that might be useful, just let me know.