SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 199

• 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

23. SDRAM Controller (SDRAMC)
23.1
23.2
6222F–ATARM–14-Jan-11
Overview
Block Diagram
The SDRAM Controller (SDRAMC) extends the memory capabilities of a chip by providing the
interface to an external 16-bit or 32-bit SDRAM device. The page size supports ranges from
2048 to 8192 and the number of columns from 256 to 2048. It supports byte (8-bit), half-word
(16-bit) and word (32-bit) accesses.
The SDRAM Controller supports a read or write burst length of one location. It does not support
byte Read/Write bursts or half-word write bursts. It keeps track of the active row in each bank,
thus maximizing SDRAM performance, e.g., the application may be placed in one bank and data
in the other banks. So as to optimize performance, it is advisable to avoid accessing different
rows in the same bank.
The SDRAM Controller also supports Mobile SDRAM if VDDIO is set at 1.8V with the frequency
limitation as given in the product Electrical Characteristics. However, the SDRAMC does not
support the low-power extended mode register and deep power-down mode.
Figure 23-1. SDRAM Controller Block Diagram
Controller
Memory
PMC
Chip Select
SDRAMC
SDRAMC
Interrupt
MCK
SDRAMC
APB
User Interface
SAM7SE512/256/32
Controller
PIO
SDCK
SDCKE
SDCS
BA[1:0]
RAS
CAS
SDWE
NBS[3:0]
A[12:0]
D[31:0]
199