Motorola MVME2400 Series - Figure 1-2. Software-Readable Header; Software-Readable Header (SRH) Switch (S3)

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Hardware Preparation and Installation
1
Software-Readable Header (SRH) Switch (S3)
Switch S3 is an eight pole single-throw switch with software readable
switch settings. These settings can be read as a register at ISA I/O address
$801 (hexadecimal). Each switch pole can be set to either logic 0 or
logic 1. A logic 0 means the switch is in the “ON” position for that
particular bit. A logic 1 means the switch is in the “OFF” position for that
particular bit. SRH Register Bit 0 is associated with Pin 1 and Pin 16 of the
SRH, and SRH Register Bit 7 is associated with Pin 8 and Pin 9 of the
SRH. The SRH is a read-only register.
If Motorola’s PowerPC firmware, PPCBug, is being used, it reserves all
bits, SRH0 to SRH7. If it is not being used, the switch can be used for other
applications.
Figure 1-2. Software-Readable Header
1
2
3
J9
System Controller Disabled
1
2
3
J9
Automatic System Controller
(factory configuration)
1
2
3
J9
System Controller Enabled
SRH0 = 0
SRH1 = 0
SRH2 = 0
SRH3 = 0
SRH4 = 0
SRH5 = 0
SRH6 = 0
SRH7 = 0
SRH0 = 1
SRH1 = 1
SRH2 = 1
SRH3 = 1
SRH4 = 1
SRH5 = 1
SRH6 = 1
SRH7 = 1
ON ON
1
1
16 16
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