66AK2L06: Trouble Halting CPU error -1321

Part Number:66AK2L06

I have a custom board designed around the 66AK2L06.

I'm using CCS v7 with an XDS100v3.

Power-up/Clocking/Reset sequence appears to be OK since I have RESET STATUS going high and a 16.666mHz clock on the SYSCLKOUT pin.

CVDD is controlling around 0.94v

Running the JTAG 'Test Connnection' has no errors.

Bootmode pins set to Sleep Mode with ARM boot and PLL/System clock set to 1Ghz (100mHz input clock).

The problem is when I try to run a short test program in debug. The GEL loads and executes but I get the following error:

ARM_A15_0: Trouble Halting CPU (Error -1321). Device failed to enter debug/halt mode because security settings prevent debug.

I'm not sure what security settings they are talking about. Any ides on what I can try to debug/fix this?

Thanks!