SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 88

• Manufacturer Part Number: SAM9G20
• Manufacturer: Atmel Corporation

Specifications of SAM9G20

• Flash (kbytes): 0 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 96
• Ext Interrupts: 96
• Usb Transceiver: 3
• Usb Speed: Full Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 1
• Uart: 7
• Ssc: 1
• Ethernet: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 95
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 0.9 to 1.1
• Fpu: No
• Mpu / Mmu: No/Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Memory Management Unit
3.4
3-24
Domain access control
MMU accesses are primarily controlled through the use of domains. There are 16
domains and each has a two-bit field to define access to it. Two types of user are
supported:
•
•
The domains are defined in the domain access control register, CP15 c3. Figure 2-7 on
page 2-18 shows how the 32 bits of the register are allocated to define the 16 two-bit
domains.
Table 3-11 defines how the bits within each domain are interpreted to specify the access
permissions.
Table 3-12 shows how to interpret the Access Permission (AP) bits and how their
interpretation is dependent on the R and S bits (Control Register c1 bits [9:8]).
Value
0 0
0 1
1 0
1 1
Copyright © 2001-2003 ARM Limited. All rights reserved.
clients
managers.
Meaning
No access
Client
Reserved
Manager
Table 3-11 Domain access control register, access control bits
AP
0 0
0 0
0 0
0 0
S
0
1
0
1
Table 3-12 Interpreting access permission (AP) bits
Description
Any access generates a domain fault.
Accesses are checked against the access permission bits in
the section or page descriptor.
Reserved. Currently behaves like the no access mode.
Accesses are not checked against the access permission
bits so a permission fault cannot be generated.
R
0
0
1
1
Privileged permissions
No access
Read-only
Read-only
Unpredictable
User permissions
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No access
Read-only
Unpredictable
ARM DDI0198D