SAM3U2C Atmel Corporation, SAM3U2C Datasheet - Page 368

• Manufacturer Part Number: SAM3U2C
• Manufacturer: Atmel Corporation

Specifications of SAM3U2C

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 96 MHz
• Cpu: Cortex-M3
• # Of Touch Channels: 28
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 57
• Ext Interrupts: 57
• Usb Transceiver: 1
• Quadrature Decoder Channels: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device
• Spi: 4
• Twi (i2c): 1
• Uart: 4
• Ssc: 1
• Sd / Emmc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 36
• Self Program Memory: YES
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 1.62 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: Yes

25.12.2
Figure 25-14. Early Read Wait State: Write with No Hold Followed by Read with No Setup
368
368
SAM3U Series
SAM3U Series
Early Read Wait State
NBS0, NBS1,
A0, A1
In some cases, the SMC inserts a wait state cycle between a write access and a read access to
allow time for the write cycle to end before the subsequent read cycle begins. This wait state is
not generated in addition to a chip select wait state. The early read cycle thus only occurs
between a write and read access to the same memory device (same chip select).
An early read wait state is automatically inserted if at least one of the following conditions is
valid:
D[15:0]
A[23:2]
• if the write controlling signal has no hold time and the read controlling signal has no setup
• in NCS write controlled mode (WRITE_MODE = 0), if there is no hold timing on the NCS
• in NWE controlled mode (WRITE_MODE = 1) and if there is no hold timing (NWE_HOLD =
NWE
MCK
NRD
time
signal and the NCS_RD_SETUP parameter is set to 0, regardless of the read mode
25-15). The write operation must end with a NCS rising edge. Without an Early Read Wait
State, the write operation could not complete properly.
0), the feedback of the write control signal is used to control address, data, chip select and
byte select lines. If the external write control signal is not inactivated as expected due to load
capacitances, an Early Read Wait State is inserted and address, data and control signals are
maintained one more cycle. See
(Figure
25-14).
write cycle
no hold
Early Read
wait state
Figure
25-16.
no setup
read cycle
6430E–ATARM–29-Aug-11
6430E–ATARM–29-Aug-11
(Figure