Cannot Connect TC399 Upgraded from TC299

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User20826
Level 1
Level 1
Hi there,
I'm trying to connect via the DAP port (miniWiggler) to a TC399 which is replacing a TC299 on one our products and am failing.
The error messages from the memtool consists of "can't connect to target" and "can't connect to device via DAS".
The DAS Device Scanner shows nothing while listing the device when a product with the TC299 is installed.
This is the first time attempting to connect to the chip and program it.

Any suggestions?
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5 Replies
VincentWan
Employee
Employee
50 replies posted 5 sign-ins First like received
Hi,

In general, we can check the following pins:

/PORST
XTAL
HWCFG
all relevant supply pins (Vdd, Vddp3, Vext, Vflex, Vddm, Vddsb, Vebu)
/ESR0
/TRST
/TESTMODE

With a debugger, we can also check the Reset Status Register (RSTSTAT) for hints.
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MoD
Employee
Employee
50 likes received 500 replies posted 100 solutions authored
You made some adaptations for replacing the TC299 with a TC399? You can't remove TC299 and assemble TC399 instead directly.
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User20826
Level 1
Level 1
Adaptations were not made, as it were.
Looking at the schematic for the TC399 eval board (sheet 5), it appears that the TLF11251 (U503) needs to be added to the 1v25 buck converter circuit, even though it's denoted as optional. Currently we're seeing oscillation on the 3v3 and 1v3 rails.
Are additional mods required to enable a 299 to 399 swap?
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MoD
Employee
Employee
50 likes received 500 replies posted 100 solutions authored
In this case you made shortcut between 3v3 and 1v3 via the TC399 itself. As I wrote you can't simple replace the TC299 by a TC399.
TC299 ball J21 and K20 are VDDFL3 and on your board connected to 3,3V. TC399 ball J21 and K20 are connected to VDD and must be connected to 1,3V. Because this balls on TC399 are connected to other VDD pins via the substrate you make here an shortcut from 3,3V to 1,3V.
This should be the reason for oscillation. Please note, I don't known if there is now any damage on the TC399 because of supplying VDD with 3,3V.
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User20826
Level 1
Level 1
Thank you very much for the prompt reply.
I'll have to get back to you at a later date once we've attempted and verified the fix.
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