GRASS VALLEY 1200, Installation And Service

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Section 3 Ñ Functional Description
System Boot
On a power up or a reset the reset line on the 68302 is pulsed low while the
reset line on the 68020 is held low. The 68302 then boots from the boot
PROM. The first step in the boot is for the processor to run diagnostics
checks. It checks its own RAM, the 68020 RAM, and does a check of the
peripherals on both processors.
If any of the diagnostics fail, LED DS9 will light and the system will hang
up in a loop trying to access the failed location. This allows easy
troubleshooting of errors. If the boot is interrupted by pressing the space
bar the system then goes into a mode which allows access to a low level
debugger or the loading of a new operating system.
After the diagnostics run, the 68302 looks for an operating system in the
flash EEPROM. If a system is found, the system is transferred to the RAM
of both processors; then the Model 1200 boots from RAM.
The field LEDs are on during the vertical interval while that processor is
reading and writing. The Background LEDs are on while that processor is
doing background tasks. Since the background tasks take up most of the
processor time, the Background LEDs will be on bright and the field LEDs
will be on dim.
When there is activity on any of the serial ports LED DS8 will flash. In
addition, there are ten LEDs which indicate activity on particular serial
ports by flashing whenever there is transmitted or received data on that
serial port.
The parameter EEPROM for the 68020 contains the setup items that do not
change much, such as the UART setups, default inputs, default matte
settings, and default proc amp settings. These settings are loaded into RAM
at bootup.
The Control Processor Module also contains all of the clock fanouts for the
Sync Pulse Submodule.
The 68302 can read and write to the 68020 RAM using the bus arbitration
circuit.
The Control Panel contains an RDY/EPC-31 Motherboard which
communicates with the control processor in the frame through the I/O
board.