SH ARC-66
Version 03.00
3.11 Boot ROM
The card can be equipped with a boot ROM (socket IC4). Therefore it is
possible to boot the computer via the network.
The jumper “ENROM” has to be plugged in. However, we recommend to
plug in the jumper even if no boot ROM is used.
The selected memory area of the boot ROM can be taken from the table
of chapter 3.8 "memory address."
4. Memory address space
The ARCNET controller superimposes at 16 addresses in the I/O area
and occupies 2 kilobytes of the main memory (Memory) (see [1]).
IO-base a Read register
Write register
0
STATUS
INTERRUPT MASK
1
DIAG. Status
COMMAND
2
CONFIGURATION
CONFIGURATION
3
I/O SELECT
RESERVED
4
MEMORY SELECT
RESERVED
5
NODE ID
NODE ID
6
RESERVED
RESERVED
7
RESERVED
EXTERNAL REGISTER
8
RESET
RESET
9
RESET
RESET
A
RESET
RESET
B
RESET
RESET
C
DATA LOW
DATA LOW
D
DATA HIGH
DATA HIGH
E
ADDRESS PTR LOW
ADDRESS PTR LOW
F
ADDRESS PTR HIGH ADDRESS PTR HIGH
Page 10
