SAM9G10 Atmel Corporation, SAM9G10 Datasheet - Page 399

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SAM9G10

Manufacturer Part Number
SAM9G10
Description
Manufacturer
Atmel Corporation
Datasheets

Specifications of SAM9G10

Flash (kbytes)
0 Kbytes
Pin Count
217
Max. Operating Frequency
266 MHz
Cpu
ARM926
Hardware Qtouch Acquisition
No
Max I/o Pins
96
Ext Interrupts
96
Usb Transceiver
3
Usb Speed
Full Speed
Usb Interface
Host, Device
Spi
2
Twi (i2c)
1
Uart
4
Ssc
3
Sd / Emmc
1
Graphic Lcd
Yes
Video Decoder
No
Camera Interface
No
Resistive Touch Screen
No
Temp. Sensor
No
Crypto Engine
No
Sram (kbytes)
16
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)
1.08 to 1.32
Fpu
No
Mpu / Mmu
No/Yes
Timers
3
Output Compare Channels
3
Input Capture Channels
3
32khz Rtc
Yes
Calibrated Rc Oscillator
No
29.10.3.2
29.10.4
29.11 Data Float Wait States
29.11.1
11053B–ATARM–22-Sep-11
11053B–ATARM–22-Sep-11
Read to Write Wait State
READ_MODE
Slow Clock Mode Transition
to unpredictable behavior. The instructions used to modify the parameters of an SMC Chip
Select can be executed from the internal RAM or from a memory connected to another CS.
A Reload Configuration Wait State is also inserted when the Slow Clock Mode is entered or
exited, after the end of the current transfer (see
Due to an internal mechanism, a wait cycle is always inserted between consecutive read and
write SMC accesses.
This wait cycle is referred to as a read to write wait state in this document.
This wait cycle is applied in addition to chip select and reload user configuration wait states
when they are to be inserted. See
Some memory devices are slow to release the external bus. For such devices, it is necessary to
add wait states (data float wait states) after a read access:
The Data Float Output Time (t
TDF_CYCLES field of the SMC_MODE register for the corresponding chip select. The value of
TDF_CYCLES indicates the number of data float wait cycles (between 0 and 15) before the
external device releases the bus, and represents the time allowed for the data output to go to
high impedance after the memory is disabled.
Data float wait states do not delay internal memory accesses. Hence, a single access to an
external memory with long t
memory.
The data float wait states management depends on the READ_MODE and the TDF_MODE
fields of the SMC_MODE register for the corresponding chip select.
Setting the READ_MODE to 1 indicates to the SMC that the NRD signal is responsible for turn-
ing off the tri-state buffers of the external memory device. The Data Float Period then begins
after the rising edge of the NRD signal and lasts TDF_CYCLES MCK cycles.
When the read operation is controlled by the NCS signal (READ_MODE = 0), the TDF field gives
the number of MCK cycles during which the data bus remains busy after the rising edge of NCS.
Figure 29-20
assuming a data float period of 2 cycles (TDF_CYCLES = 2).
ation when controlled by NCS (READ_MODE = 0) and the TDF_CYCLES parameter equals 3.
• before starting a read access to a different external memory
• before starting a write access to the same device or to a different external one.
illustrates the Data Float Period in NRD-controlled mode (READ_MODE =1),
DF
will not slow down the execution of a program from internal
DF
Figure 29-16 on page
) for each external memory device is programmed in the
“Slow Clock Mode” on page
396.
Figure 29-21
shows the read oper-
409).
SAM9G35
SAM9G35
399
399

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