9 / 82 page

9
9
FIGURE 2 – COM20051 EXTERNAL DATA ADDRESS SPACE
ADDRESS DECODE REGISTER
NAME
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
ADR DEC
A15
A14
A13
A12
A11
A10
A9
A8
LOCATION: FFFFh of the External Data Memory space. Default: 00h
EXAMPLE:
Address Decode Register = 80h
ARCNET core registers will be located at 8000h + Register offset (e.g. ARCNET
Configuration Register offset = 06h, physical address = 8006h).
ARCNET CORE
256 BYTES
FFFFh
64K
BYTES
ADDRESS DECODE
REGISTER
(FIXED LOCATION)
PAGE
LOCATION CAN
VARY
VALUE x 100h
0000h