MC7455 Auto-SIM function issue

IoT Modules MC/EM Series
1

I have loaded firmware and PRI for a number of carriers:

at!image?
TYPE SLOT STATUS LRU FAILURES UNIQUE_ID   BUILD_ID
FW   1    GOOD   4   0 0      ?_?         02.20.03.22_?
FW   2    GOOD   1   0 0      ?_?         02.05.07.00_?
FW   3    GOOD   1   0 0      ?_?         02.14.03.02_?
FW   4    GOOD   5   0 0      ?_?         02.24.03.00_?
Max FW images: 4
Active FW image is at slot 4

TYPE SLOT STATUS LRU FAILURES UNIQUE_ID   BUILD_ID
PRI  FF   GOOD   0   0 0      002.022_000 02.24.03.00_ATT
PRI  FF   GOOD   0   0 0      001.001_000 02.24.03.00_BELL
PRI  FF   GOOD   0   0 0      002.021_000 02.24.03.00_GENERIC
PRI  FF   GOOD   0   0 0      001.001_000 02.24.03.00_ROGERS
PRI  FF   GOOD   0   0 0      002.022_000 02.24.03.00_SPRINT
PRI  FF   GOOD   0   0 0      001.000_000 00.00.00.00_OEMPRI918
PRI  FF   GOOD   0   0 0      001.001_000 02.24.03.00_TELUS
PRI  FF   GOOD   0   0 0      002.026_001 02.20.03.22_VERIZON
PRI  FF   GOOD   0   0 0      001.001_000 02.24.03.00_VODAFONE
Max PRI images: 50

I can switch between them using AT!IMPREF= and an AT!RESET all fine.

However, when I turn AUTO-SIM on (my desired operating mode), the MC7455 does not change firmware, and gets into a reset loop over and over again, basically never loading/changing the firmware, and in turn starting again, seeing a mismatch, and then restarting again. This goes on forever.

While this reset loop is happening, my test scenario is I have ATT firmware selected/active. I then turn on AUTO-SIM with a T-Mobile SIM card inserted, and perform an AT!RESET.

Here is the status mid-reset:

at!impref?
!IMPREF: 
 preferred fw version:    00.00.00.00
 preferred carrier name:  AUTO-SIM
 preferred config name:   AUTO-SIM_000.000_000
 current fw version:      02.24.03.00
 current carrier name:    ATT
 current config name:     ATT_002.022_000

 carrier name mismatch
 config name mismatch

OK

T-Mobile should switch the current FW back to GENERIC, but it doesn’t seem to happen, and in turn, the MC7455 resets itself again.

Anyone have AUTO-SIM working OK. Our hardware does not have SIM DETECT connected, so the following should apply:

ON MC7455 and EM7455 (without SIM DETECT line connected):
 When the module is powered ON and a new SIM is inserted, the host has to reset the module (AT!RESET or
SetPower()) to trigger a FW switch.
 If the module is powered OFF when a new SIM is inserted, then the FW detects the need for a FW switch during boot
time. It triggers a reset to activate the correct FW + carrier PRI (needs Release 16 FW which has bugs addressed).

Using !reset, or power off/on does not effect the reset loop.

I assume the note about using > FW 16 means 2.16…?

Thanks for any help!

2

Another minor note to this, I just had issue changing from ATT to GENERIC using the !IMPREF command directly.

The IMPREF returned OK, but after the reset, still showed current firmware ATT and preferred firmware GENERIC. The MC7455 was not actually making the switch to the requested firmware.

I then set IMPREF=“ATT” and did a reset, all looked fine.

Then set IMPREF=“GENERIC” and did a reset, and this time it also looked fine.

Seems like the MC7455 is getting into a strange state after trying to use the auto-sim feature. Perhaps will call our distributor as this seems like it might be a bug.

3

Adding one piece of additional info based on another issue earlier with AUTO-SIM.

The MC7455 I am working with is Rev C.

The firmware is >.20 based on that earlier thread, so not sure why I am having an issue.

4

Bringing up an old post. I am experiencing the same issues with an EM7455 trying to get Dual SIM to work on an EM7455 . I am using a REV C model as well. I have both Verizon and Sprint SIM’s and am unable to get 2nd SIM to work properly.