SAM9XE256 Atmel Corporation, SAM9XE256 Datasheet - Page 74

• Manufacturer Part Number: SAM9XE256
• Manufacturer: Atmel Corporation

Specifications of SAM9XE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 180 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): 2
• Uart: 6
• 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): 312
• 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): 1.65 to 1.95
• 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
3.2.4
3-10
Section descriptor
31
Bits
Section
[3:2]
-
[1:0]
The two least significant bits of the first-level descriptor indicate the descriptor type as
shown in Table 3-3.
A section descriptor provides the base address of a 1MB block of memory. Figure 3-5
shows the format of a section descriptor.
Section base address
Value
0 0
0 1
1 0
1 1
Copyright © 2001-2003 ARM Limited. All rights reserved.
Coarse
-
[3:2]
[1:0]
Meaning
Invalid
Coarse page table
Section
Fine page table
Fine
-
[3:2]
[1:0]
20 19
Table 3-3 Interpreting first-level descriptor bits [1:0]
Description
Bits C and B indicate whether the area of memory mapped
by this page is treated as write-back cachable, write-through
cachable, noncached buffered, or noncached nonbuffered.
Should Be Zero.
These bits indicate the page size and validity and are
interpreted as shown in Table 3-3.
Generates a section translation fault
Description
Indicates that this is a coarse page table descriptor
Indicates that this is a section descriptor
Indicates that this is a fine page table descriptor
Table 3-2 First-level descriptor bits (continued)
SBZ
12 11 10 9 8
AP
Figure 3-5 Section descriptor
S
B
Z
Domain
5 4 3 2 1 0
1 C B 1
ARM DDI0198D
0