SAM9XE256 Atmel Corporation, SAM9XE256 Datasheet - Page 120

• 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

Tightly-Coupled Memory Interface
5-12
In cycle T1, the ARM926EJ-S internal TCM controller is idle and DRIDLE is asserted.
DRDMAEN is asserted, and consequently the value of DRDMAADDR is propagated
onto DRADDR, and DRCS is asserted (DRDMACS = 1). DRSEQ is forced LOW.
In cycle T2, the ARM926EJ-S internal TCM controller is no longer idle, and DRIDLE
is deasserted. A nonsequential request is made to address B.
In cycle T3, a sequential request is made to address B+1 and DRSEQ is asserted
In cycle T4, the ARM926EJS internal TCM controller attempts to output values
corresponding to a sequential request to address B+2. DRDMAEN is asserted, and the
value of DRADDR and DRSEQ change accordingly. The ARM926EJ-S TCM
controller is stalled.
In cycle T5, DRDMAEN is deasserted and the ARM926EJ-S TCM controller re-issues
the request to address B+2. Because of the intervening DMA access, DRSEQ is
deasserted for the repeated request.
In cycle T6, a sequential request is made to address B+3 and DRSEQ is re-asserted.
DMA accesses can be made to the ITCM using the IRDMAEN, IRDMACS, and
IRDMAADDR signals but, unlike the DTCM, simultaneous access by the
ARM926EJ-S and DMA is not supported. This means that ITCM DMA must not take
place while executing code from the ITCM.
DRDMAADDR
DRDMAEN
DRDMACS
Copyright © 2001-2003 ARM Limited. All rights reserved.
DRADDR
DRIDLE
DRSEQ
DRCS
CLK
Figure 5-5 DMA access interaction with normal DTCM accesses
T1
A
A
T2
B
T3
B+1
B+2
T4
C
C
T5
B+2
ARM DDI0198D
T6
B+3
B+3