SAM9G20 Atmel Corporation, SAM9G20 Datasheet - Page 207

• 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

Figure 22-3. Read Burst, 32-bit SDRAM Access
6384E–ATARM–05-Feb-10
SDRAMC_A[12:0]
D[31:0]
SDWE
SDCS
(Input)
SDCK
RAS
CAS
For a single access or an incremented burst of unspecified length, the SDRAM Controller antici-
pates the next access. While the last value of the column is returned by the SDRAM Controller
on the bus, the SDRAM Controller anticipates the read to the next column and thus anticipates
the CAS latency. This reduces the effect of the CAS latency on the internal bus.
For burst access of specified length (4, 8, 16 words), access is not anticipated. This case leads
to the best performance. If the burst is broken (border, busy mode, etc.), the next access is han-
dled as an incrementing burst of unspecified length.
Row n
t
RCD
= 3
col a
CAS = 2
col b
Dna
col c
Dnb
col d
Dnc
col e
Dnd
col f
Dne
AT91SAM9G20
Dnf
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