C. System Registers
75
Event Monitors (E1h)
I/O Address:
E1h
Default Value: 0x00
Size: 8
bits
Attribute: RO
Bit Description
7
RESERVED
6
ENUM-
This bit displays the value of ENUM- from backplane
J1
-C25. A logical 0 means that
ENUM- is not asserted on the backplane. A logical 1 means that ENUM- is asserted
on the backplane.
5:0
RESERVED
Switch Monitors (E3h)
Address Offset: E3h
Default Value:
0x80
Size: 8
bits
Attribute: RO
Bit Description
7
Flash Write-Protect Status
This bit corresponds to the status of switch
SW3-2
. A logical 0 means that the flash
is write-protected by SW3-2; a logical 1 means the flash is
not
write-protected by
SW3-2.
6
System Enable
This bit corresponds to the status of SYSEN. A logical 1 indicates that the ZT 5504
is plugged into a system slot. A logical 0 indicates that the ZT 5504 is plugged into a
peripheral slot.
5
RESERVED
4
Manufacturing Mode
This bit is used during production testing to load a default CMOS image. A logical 1
indicates manufacturing mode. A logical 0 indicates non-manufacturing mode.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
