)
Values for ECB in use flag:
 00h	available
 E0h	AES temporary
 F6h	\ special IPX/SPX processing for v3.02+
 F7h	/
 F8h	IPX in critical section
 F9h	SPX listening
 FAh	processing
 FBh	holding
 FCh	AES waiting
 FDh	AES couting down delay time
 FEh	awaiting packet reception
 FFh	sending packet
SeeAlso: #03810,#03811,#03813