SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 203

• Manufacturer Part Number: SAM7SE256
• Manufacturer: Atmel Corporation

Specifications of SAM7SE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 48 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 88
• Ext Interrupts: 88
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• 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): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Figure 23-2. SDRAM Devices Initialization Sequence
23.5.2
23.5.3
6222F–ATARM–14-Jan-11
SDRAMC_A[12:11]
SDRAMC_A[9:0]
SDCKE
SDWE
SDCK
SDCS
RAS
CAS
NBS
A10
I/O Lines
Interrupt
Inputs Stable for
200 μsec
The pins used for interfacing the SDRAM Controller may be multiplexed with the PIO lines. The
programmer must first program the PIO controller to assign the SDRAM Controller pins to their
peripheral function. If I/O lines of the SDRAM Controller are not used by the application, they can
be used for other purposes by the PIO Controller.
The SDRAM Controller interrupt (Refresh Error notification) is connected to the Memory Control-
ler. This interrupt may be ORed with other System Peripheral interrupt lines and is finally
provided as the System Interrupt Source (Source 1) to the AIC (Advanced Interrupt Controller).
Using the SDRAM Controller interrupt requires the AIC to be programmed first.
Precharge All Banks
t
RP
1st Auto-refresh
8th Auto-refresh
t
RC
SAM7SE512/256/32
MRS Command
t
MRD
Valid Command
203