Setting The General-Purpose Software-Readable Header (Srh) Switch(S3); Figure 1-2. General-Purpose Software-Readable Header - Motorola MVME2401-1 Installation And Use Manual

Automatic System Controller
(factory configuration)

Setting the General-Purpose 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.
1
ON

Figure 1-2. General-Purpose Software-Readable Header

http://www.mcg.mot.com/literature
J9
1
2
3
System Controller Enabled
16
SRH0 = 0
SRH1 = 0
SRH2 = 0
SRH3 = 0
SRH4 = 0
SRH5 = 0
SRH6 = 0
SRH7 = 0
Preparing the MVME240x Hardware
J9
1
2
3
System Controller Disabled
1
ON
J9
1
2
3
16
SRH0 = 1
SRH1 = 1
SRH2 = 1
SRH3 = 1
SRH4 = 1
SRH5 = 1
SRH6 = 1
SRH7 = 1
1-11
1