Address decoding – Digi NS9215 User Manual

Page 141

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S Y S T E M C O N T R O L M O D U L E

Address decoding

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141

BRC1[23:16] = 8’b1_0_00_0000

channel disabled

BRC1[15:8]

= 8’b1_0_00_0000

channel disabled

BRC1[7:0]

= 8’b1_0_00_0000

channel disabled

BRC2[31:24] = 8’b0_0_00_0000

channel disabled

BRC2[23:16] = 8’b0_0_00_0000

channel disabled

BRC2[15:8]

= 8’b0_0_00_0000

channel disabled

BRC2[7:0]

= 8’b0_0_00_0000

channel disabled

BRC3[31:24] = 8’b0_0_00_0000

channel disabled

BRC3[23:16] = 8’b0_0_00_0000

channel disabled

BRC3[15:8]

= 8’b0_0_00_0000

channel disabled

BRC[7:0]

= 8’b0_0_00_0000

channel disabled

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A d d r e s s d e c o d i n g

A central address decoder provides a select signal —

hsel_x

— for each slave on the

bus.

This table shows how the system memory address is set up to allow access to the
internal and external resources on the system bus. Note that the external memory
chip select ranges can be reset after powerup. The table shows the default powerup
values; you can change the ranges by writing to the BASE and MASK registers (see
“System Memory Chip Select 0 Dynamic Memory Base and Mask registers” on
page 190
through “System Memory Chip Select 3 Dynamic Memory Base and Mask
registers” on page 193 for
more information).

Address range

Size

System functions

0x0000 0000 – 0x0FFF FFFF

256 MB

System memory chip select 0
Dynamic memory (default)

0x1000 0000 – 0x1FFF FFFF

256 MB

System memory chip select 1
Dynamic memory (default)

0x2000 0000 – 0x2FFF FFFF

256 MB

System memory chip select 2
Dynamic memory (default)

0x3000 0000 – 0x3FFF FFFF

256 MB

System memory chip select 3
Dynamic memory (default)

0x4000 0000 – 0x4FFF FFFF

256 MB

System memory chip select 0
Static memory (default)

0x5000 0000 – 0x5FFF FFFF

256 MB

System memory chip select 1
Static memory (default)

0x6000 0000 – 0x6FFF FFFF

256 MB

System memory chip select 2
Static memory (default)

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