SAM7S256 Atmel Corporation, SAM7S256 Datasheet - Page 100

• Manufacturer Part Number: SAM7S256
• Manufacturer: Atmel Corporation

Specifications of SAM7S256

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 55 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• 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): 64
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• 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: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Memory Interface
3-30
nMREQ
A[31:0]
D[31:0]
nWAIT
MCLK
nRAS
nCAS
When designing a memory controller, you are strongly advised to sample the values of
nMREQ, SEQ, and the address class signals only when nWAIT is HIGH. This ensures
that the state of the memory controller is not accidentally updated during an extended
bus cycle.
nRW
SEQ
A
Note
Copyright © 1994-2001. All rights reserved.
A+4
S
Cycles
A+8
S
Decode
B
N
B+4
Cycles
S
B+8
Figure 3-21 Typical system timing
S
Decode
C
N
ARM DDI 0029G
Cycles
C+4
S