https://community.nxp.com/t5/i-MX-Processors/imx6ull-cannot-jtag-debugging-in-emmc-startup-mode/m-p/1217591#M168050 <P>You can use Serial Downloader mode as Igor suggested. For the details please refer to chapter 8.9 "Serial Downloader" of the Reference Manual.</P> Wed, 20 Jan 2021 04:07:11 GMT b36401 2021-01-20T04:07:11Z https://community.nxp.com/t5/i-MX-Processors/imx6ull-cannot-jtag-debugging-in-emmc-startup-mode/m-p/1212915#M167876 imx6ull cannot jtag debugging in emmc startup mode,jtag show Device "MCIMX6Y2" selected. Connecting to target via JTAG ConfigTargetSettings() start J-Link script: Setting up AP map ConfigTargetSettings() end Could not measure total IR len. TDO is constant high. ConfigTargetSettings() start J-Link script: Setting up AP map ConfigTargetSettings() end Could not measure total IR len. TDO is constant high. ConfigTargetSettings() start J-Link script: Setting up AP map ConfigTargetSettings() end Could not measure total IR len. TDO is constant high. ConfigTargetSettings() start J-Link script: Setting up AP map ConfigTargetSettings() end Could not measure total IR len. TDO is constant high. Cannot connect to target. but Serial Downloader mode can jtag debug why? Mon, 18 Jan 2021 03:37:26 GMT https://community.nxp.com/t5/i-MX-Processors/imx6ull-cannot-jtag-debugging-in-emmc-startup-mode/m-p/1212915#M167876 debugall 2021-01-18T03:37:26Z https://community.nxp.com/t5/i-MX-Processors/imx6ull-cannot-jtag-debugging-in-emmc-startup-mode/m-p/1217591#M168050 <P>You can use Serial Downloader mode as Igor suggested. For the details please refer to chapter 8.9 "Serial Downloader" of the Reference Manual.</P> Wed, 20 Jan 2021 04:07:11 GMT https://community.nxp.com/t5/i-MX-Processors/imx6ull-cannot-jtag-debugging-in-emmc-startup-mode/m-p/1217591#M168050 b36401 2021-01-20T04:07:11Z