I am trying to upload a program in cortex m4 u sing ulink2. I have connected vcc gnd swdio and swdclk from cortex m4 to jtag 20 pin connector but the com port is not showing on pc. I also supplied power that is vcc gnd from a power source to cortex m4 processor but still no result.Also 3.3 v is not coming from jtag when it is plugged in.Please guide what to do.
You seem to have very little grasp of the hardware you are working with.
The Segger J-Link can provide 5V via pin 19, the ST-LINK 3.3V, but this isn't exactly standard, and not on the U-LINKs They also don't provide a COM port or UART. What pins of the 20-pin header does your board use? The CM4 can provide a SWV channel via TDO/SWO pin, but this isn't technically a COM port you can open with a terminal.
Perhaps you can provide a cite for the web pages you've collected this mismash of information from, and which describes the connectors on your board.
I connected vcc gnd swdio and swdclk to the 20 pin jtag connector which is connected to ulink2. link for reference (page 22 and 23): www.mouser.in/.../Laird_09102018_Datasheet-BL651_prelimv0_01.pdf Can the segger j link provide com port also?
I haven't shopped Segger recently. Just use a USB-to-CMOS Serial adapter, ie SiLabs, FTDI, etc
Segger have a whole range of different "J-Link" models with different capabilities.
Segger is an independent 3rd party - nothing to do with Keil or ARM.
You can find out about Segger products on their website: www.segger.com/.../