SAM9G45 Atmel Corporation, SAM9G45 Datasheet - Page 100

• Manufacturer Part Number: SAM9G45
• Manufacturer: Atmel Corporation

Specifications of SAM9G45

• Flash (kbytes): 0 Kbytes
• Pin Count: 324
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 160
• Ext Interrupts: 160
• Usb Transceiver: 3
• Usb Speed: Hi-Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 2
• Uart: 5
• Lin: 4
• Ssc: 2
• Ethernet: 1
• Sd / Emmc: 2
• Graphic Lcd: Yes
• Video Decoder: No
• Camera Interface: Yes
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 440
• Resistive Touch Screen: Yes
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 64
• Self Program Memory: NO
• External Bus Interface: 2
• Dram Memory: DDR2/LPDDR, SDRAM/LPSDR
• 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
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Caches and Write Buffer
4.2
4-4
Write buffer
The write buffer is used for all writes to a noncachable, bufferable region, write-through
region, and write misses to a write-back region. A separate buffer is incorporated in the
DCache for holding write-back data for cache line evictions or cleaning of dirty cache
lines.
The main write buffer has a 16-word data buffer and a four-address buffer.
The DCache write-back buffer has eight data word entries and a single address entry.
The MCR drain write buffer instruction enables both write buffers to be drained under
software control.
The MCR wait for interrupt causes both write buffers to be drained and the
ARM926EJ-S processor to be put into a low-power state until an interrupt occurs.
Write buffer behavior is described in Table 4-4 on page 4-6.
No forwarding takes place for read accesses which have corresponding pending writes
in the write buffer. For such accesses the write buffer is drained and the value fetched
from external memory.
Copyright © 2001-2003 ARM Limited. All rights reserved.
ARM DDI0198D