They appear to be referring to the CAAM. You need to read the Vybrid Security Reference manual; especially chapter 14. The 'DECO' is a job descriptor for the encryption engine. Both erratas are grouped in the same part of the errata manual; this usually indicates that they come from a similar functional block. A better question might be, Where is the SEC Programmer's Reference Manual? Most of the chapter 14 gives details. I guess maybe SEC Programmer's Reference Manual, means the 'Vybrid Security Reference manual'?
Briefly, a DECO is given to a JOB QUEUE and work is done. There maybe multiple JOBS/DECOs at the same time. See: Linux CAAM driver where you can see both 'JOB RINGs' and 'DECOs' being used in the source.
