JLinkExe -device STM32F407VG -if SWD -speed 4000
SEGGER J-Link Commander V6.62a (Compiled Jan 31 2020 12:58:00)
DLL version V6.62a, compiled Jan 31 2020 12:57:49

Connecting to J-Link via USB...O.K.
Firmware: J-Link ARM V8 compiled Nov 28 2014 13:44:46
Hardware version: V8.00
S/N: <censored>
License(s): FlashBP, GDB
OEM: SEGGER-EDU
VTref=3.293V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Device "STM32F407VG" selected.


Connecting to target via SWD
Found SW-DP with ID 0x2BA01477
Found SW-DP with ID 0x2BA01477
Unknown DP version. Assuming DPv0
Scanning AP map to find all available APs
AP[1]: Stopped AP scan as end of AP map has been reached
AP[0]: AHB-AP (IDR: 0x24770011)
Iterating through AP map to find AHB-AP to use
AP[0]: Core found
AP[0]: AHB-AP ROM base: 0xE00FF000
CPUID register: 0x410FC241. Implementer code: 0x41 (ARM)
Found Cortex-M4 r0p1, Little endian.
FPUnit: 6 code (BP) slots and 2 literal slots
CoreSight components:
ROMTbl[0] @ E00FF000
ROMTbl[0][0]: E000E000, CID: B105E00D, PID: 000BB00C SCS-M7
ROMTbl[0][1]: E0001000, CID: B105E00D, PID: 003BB002 DWT
ROMTbl[0][2]: E0002000, CID: B105E00D, PID: 002BB003 FPB
ROMTbl[0][3]: E0000000, CID: B105E00D, PID: 003BB001 ITM
ROMTbl[0][4]: E0040000, CID: B105900D, PID: 000BB9A1 TPIU
ROMTbl[0][5]: E0041000, CID: B105900D, PID: 000BB925 ETM
Cortex-M4 identified.
J-Link>erase
Erasing device...

****** Error: Failed to prepare for programming.
RAM check failed @ addr 0x20000ADC.
RAM check failed while testing 0x2050 bytes @ addr 0x200006CC.
ERROR: Erase returned with error code -1.
J-Link>erase
Erasing device...
Comparing flash   [100%] Done.
Erasing flash     [100%] Done.
J-Link: Flash download: Total time needed: 8.631s (Prepare: 0.091s, Compare: 0.000s, Erase: 8.536s, Program: 0.000s, Verify: 0.000s, Restore: 0.003s)
Erasing done.
J-Link>