viii
Autoboot ............................................................................................................ 2-8
ROMboot ........................................................................................................... 2-9
Network Boot .................................................................................................. 2-10
Reset ................................................................................................................ 2-11
Abort ................................................................................................................ 2-12
Break ............................................................................................................... 2-12
Components of the Firmware ................................................................................... 3-2
Memory Requirements ............................................................................................. 3-2
Implementation ......................................................................................................... 3-3
Using the Debugger .................................................................................................. 3-3
Debugger Commands ............................................................................................... 3-5
Overview .................................................................................................................. 4-1
CNFG - Configure Board Information Block ........................................................... 4-2
ENV - Set Environment ............................................................................................ 4-3
Processor and Memory ...................................................................................... 5-2
I/O Implementation ........................................................................................... 5-3
ASICs ................................................................................................................ 5-3
Data Bus Structure ............................................................................................. 5-4
Microprocessor .................................................................................................. 5-4
Memory Options ................................................................................................ 5-5
DRAM ........................................................................................................ 5-6
SRAM ........................................................................................................ 5-6
EPROM ...................................................................................................... 5-6
Battery-Backed-Up RAM and Clock ................................................................ 5-7