SBS Technologies 466-1, Hardware Manual

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Model 466-1 Adapter
4 Adapter Functions
SBus - VMEbus Timeout:
SBus to VMEbus transfer cycles timeout within 720 SBus clock cycles (28.8
µ
sec with 25 MHz SBus clock, or 36
µ
sec with a 20 MHz SBus clock). This
results in an error bit being set and an interrupt generated if enabled.
The timeout period is implemented by asserting a retry acknowledgment at
240 SBus clock cycles after the SBus system initiates a VMEbus access. After
two retries, if there is still no response from the VMEbus, the adapter issues a
false acknowledgment, sets an error status bit, and generates an interrupt.
VMEbus System Controller Capability:
If configured as the system controller, the VMEbus adapter card provides level
3 bus arbitration, generates the VMEbus system clock and reset, and detects
VMEbus timeout.
SBus Configuration ROM:
The SBus Configuration ROM includes driver and card information.
Read-Modify-Write:
Read-modify-write transactions from VMEbus to local dual-port memory are
indivisible.
Read-modify-write to the VMEbus system is simulated by a bus-lock control
bit in an adapter control register.
Conformance:
The VMEbus adapter card meets IEEE 1014C specifications.
The SBus adapter card meets Revision B.0 of the SBus specification and does
not use any of the extensions.
Power Requirements:
The VMEbus adapter card draws 3.5A at 5V.
The SBus adapter card draws 1.0A at 5V.
Environment:
Temperature: 0º to 60º C operating;
-40º to 85º C storage.
Humidity: 0% to 90% non-condensing.