System Initialization
3-10
Élan™SC520 Microcontroller User’s Manual
Figure 3-2
Programmable Address Region (PAR) Register Format
31
30
29
Target Device
0
0
0
Window disabled
0
0
1
GP bus I/O
0
1
0
GP bus memory
0
1
1
PCI bus (applies to
memory cycles to
PAR 0–PAR 1 only)
1
0
0
BOOTCS (ROM)
1
0
1
ROMCS1
1
1
0
ROMCS2
1
1
1
SDRAM
Programmable Address Region Register
31–29
28–26
25
24–0
Target of the
PAR Window
(TARGET)
Attribute
(ATTR)
Page Size
(PG_SZ)
Region Size/Start Address
(SZ_ST_ADR)
28
27
26
GP Bus Chip Select
0
0
0
GPCS0
0
0
1
GPCS1
0
1
0
GPCS2
0
1
1
GPCS3
1
0
0
GPCS4
1
0
1
GPCS5
1
1
0
GPCS6
1
1
1
GPCS7
28
27
26
ROM/SDRAM Attribute
0 = Write-enabled region
1 = Write-protected region
0 = Cacheable region
1 = Noncacheable region
0 = Code execution permitted
1 = Code execution denied
25
Memory Page Size
0
4-Kbyte memory page size on 4-Kbyte
boundary, ignored for I/O cycles.
1
64-Kbyte memory page size on 64-Kbyte
boundary, ignored for I/O cycles.
Memory
Cycle
When
[25]=0
24–18
17–0
Size defines up to 128
pages of 4-Kbyte size each,
on 4-Kbyte boundary, for a
512-Kbyte maximum win-
dow size.
Region Size
[6–0]
Start Address
A[29–12]
Memory
Cycle
When
[25]=1
24–14
13–0
Size defines up to 2K pages
of 64-Kbyte size each on 64-
Kbyte boundary, for a 128-
Mbyte maximum window
size.
Region Size
[10–0]
Start Address
A[29–16]
I/O
Cycles
Only
24–16
15–0
Size defines up to 512 bytes
with byte resolution in 64-
Kbyte I/O space.
Region Size
[8–0]
Start Address
A[15–0]
If Target is GP bus
If Target is ROM or SDRAM
Содержание Elan SC520
Страница 1: ...lan SC520 Microcontroller User s Manual Order 22004A...
Страница 4: ...iv lan SC520 Microcontroller User s Manual...
Страница 28: ...Introduction xxviii lan SC520 Microcontroller User s Manual...
Страница 42: ...Architectural Overview 1 14 lan SC520 Microcontroller User s Manual...
Страница 78: ...System Initialization 3 22 lan SC520 Microcontroller User s Manual...
Страница 108: ...Clock Generation and Control 5 10 lan SC520 Microcontroller User s Manual...
Страница 118: ...Reset Generation 6 10 lan SC520 Microcontroller User s Manual...
Страница 148: ...System Arbitration 8 24 lan SC520 Microcontroller User s Manual...
Страница 214: ...SDRAM Controller 10 36 lan SC520 Microcontroller User s Manual...
Страница 230: ...Write Buffer and Read Buffer 11 16 lan SC520 Microcontroller User s Manual...
Страница 288: ...GP Bus DMA Controller 14 22 lan SC520 Microcontroller User s Manual...
Страница 316: ...Programmable Interval Timer 16 8 lan SC520 Microcontroller User s Manual...
Страница 328: ...Software Timer 18 4 lan SC520 Microcontroller User s Manual...
Страница 346: ...Real Time Clock 20 12 lan SC520 Microcontroller User s Manual...
Страница 360: ...UART Serial Ports 21 14 lan SC520 Microcontroller User s Manual...
Страница 414: ...AMDebug Technology 26 8 lan SC520 Microcontroller User s Manual...