Force Computers SYS68K/CPU-40, User Manual

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SYS68K/CPU-40/41 USER'S MANUAL FORCE COMPUTERS
2-2
_access_control_flags:
The BUSY semaphore has to be set to indicate the readiness of the Command Control Buffer
to be processed; all other semaphores within the Access Control Field have to be left unaffected.
command:
The value $00 indicates that the Command Control Buffer is used to issue the OPEN command
through the Application Command Interface.
logical_device_number:
The logical device code denotes the device the application likes to communicate with. The
Application Command Interface translates this code using all information provided by the EAGLE
Module Software Interface to determine the appropriate physical device. The application can
obtain a list of logical device numbers, relating to a group of physical devices with the same
functional characteristics using the SERVICE command GET LOGICAL DEVICE NUMBER.
inquiry_mode:
The inquiry mode describes the way the application prefers to gain the attention of the
Application Command Interface when it will issue subsequent commands. Virtually, the Application
Command Interface's attention is gained by the generation of a specific interrupt on the
corresponding base board which may be one of the following interrupts:
!
one of the seven VMEbus interrupts, or
!
one of the two FORCE Message Broadcast interrupts, or
!
one of the eight Mailbox interrupts.
The least significant eight bits of the inquiry mode contain the major interrupt number and the
minor interrupt number as shown in Figure 2. The major interrupt number specifies the interrupt
class - one of the interrupts listed above -, whereas the minor interrupt number specifies which
of the interrupts in the class is being used. Refer to Table 1 for a list of the different major and
minor interrupt numbers.
Figure 2: The inquiry and response mode
31 24 23 16 15 8 7 4 3 0
Reserved Vector Number IRQ Level Major Interrupt Minor Interrupt
Number Number