I'm trying to configure the TC387 target for the sleep mode to get the lowest power consumption
With a successful transition to the sleep mode, I see the consumed ampere is not reduced significantly, just from 180 to 155 mA.
Even with configuring the Gpt12, Ccu60, and Ccu61 to be turned off during the sleep mode, and enabled the EvrcLPMOnSleep parameter for the sleep mode, but didn't see any difference in the consumed ampere at all.
What are the main aspects and power consumer modules shall be switched off during the sleep mode to reduce the power consumption
For the lowest power consumption, you can use the standby mode. You can refer to the following application notes.