ATSAM3S4AA-MU Atmel, ATSAM3S4AA-MU Datasheet - Page 377

• Manufacturer Part Number: ATSAM3S4AA-MU
• Description: IC MCU 32BIT 256KB FLASH 48QFN
• Manufacturer: Atmel
• Series: SAM3Sr

Specifications of ATSAM3S4AA-MU

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 64MHz
• Connectivity: I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.62 V ~ 1.95 V
• Data Converters: A/D 8x10/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 48-VQFN Exposed Pad, 48-HVQFN, 48-SQFN, 48-DHVQFN
• Processor Series: ATSAM3x
• Core: ARM Cortex M3
• 3rd Party Development Tools: JTRACE-CM3, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: ATSAM3S-EK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

23.10 Automatic Wait States
23.10.1
Figure 23-13. Chip Select Wait State between a Read Access on NCS0 and a Write Access on NCS2
23.10.2
6500C–ATARM–8-Feb-11
Chip Select Wait States
Early Read Wait State
A[23:0]
D[7:0]
NCS0
NCS2
NWE
MCK
NRD
When multiple chip selects are handled, it is possible to configure the scrambling function per
chip select using the OCMS field in the SMC_OCMS registers.
Under certain circumstances, the SMC automatically inserts idle cycles between accesses to
avoid bus contention or operation conflict.
The SMC always inserts an idle cycle between 2 transfers on separate chip selects. This idle
cycle ensures that there is no bus contention between the de-activation of one device and the
activation of the next one.
During chip select wait state, all control lines are turned inactive: NWR, NCS[0..3], NRD lines are
all set to 1.
Figure 23-13
Select 2.
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:
illustrates a chip select wait state between access on Chip Select 0 and Chip
NRD_CYCLE
Read to Write
Wait State
Chip Select
Wait State
SAM3S Preliminary
NWE_CYCLE
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