SAM3S1B Atmel Corporation, SAM3S1B Datasheet - Page 61

no-image

SAM3S1B

Manufacturer Part Number
SAM3S1B
Description
Manufacturer
Atmel Corporation
Datasheets

Specifications of SAM3S1B

Flash (kbytes)
64 Kbytes
Pin Count
64
Max. Operating Frequency
64 MHz
Cpu
Cortex-M3
# Of Touch Channels
23
Hardware Qtouch Acquisition
No
Max I/o Pins
34
Ext Interrupts
34
Usb Transceiver
1
Quadrature Decoder Channels
1
Usb Speed
Full Speed
Usb Interface
Device
Spi
3
Twi (i2c)
2
Uart
4
Ssc
1
Sd / Emmc
1
Graphic Lcd
No
Video Decoder
No
Camera Interface
No
Adc Channels
10
Adc Resolution (bits)
12
Adc Speed (ksps)
1000
Analog Comparators
1
Resistive Touch Screen
No
Dac Channels
2
Dac Resolution (bits)
12
Temp. Sensor
Yes
Crypto Engine
No
Sram (kbytes)
16
Self Program Memory
YES
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
10.5.6.1
10.5.7
10.5.7.1
10.5.7.2
6500C–ATARM–8-Feb-11
Synchronization primitives
Little-endian format
A Load-Exclusive instruction
A Store-Exclusive instruction
In little-endian format, the processor stores the least significant byte of a word at the lowest-
numbered byte, and the most significant byte at the highest-numbered byte. For example:
The Cortex-M3 instruction set includes pairs of synchronization primitives. These provide a non-
blocking mechanism that a thread or process can use to obtain exclusive access to a memory
location. Software can use them to perform a guaranteed read-modify-write memory update
sequence, or for a semaphore mechanism.
A pair of synchronization primitives comprises:
Used to read the value of a memory location, requesting exclusive access to that location.
Used to attempt to write to the same memory location, returning a status bit to a register. If this
bit is:
0: it indicates that the thread or process gained exclusive access to the memory, and the write
succeeds,
1: it indicates that the thread or process did not gain exclusive access to the memory, and no
write is performed,
The pairs of Load-Exclusive and Store-Exclusive instructions are:
Software must use a Load-Exclusive instruction with the corresponding Store-Exclusive
instruction.
To perform a guaranteed read-modify-write of a memory location, software must:
Address A
• the word instructions LDREX and STREX
• the halfword instructions LDREXH and STREXH
• the byte instructions LDREXB and STREXB.
• Use a Load-Exclusive instruction to read the value of the location.
• Update the value, as required.
• Use a Store-Exclusive instruction to attempt to write the new value back to the memory
location, and tests the returned status bit. If this bit is:
0: The read-modify-write completed successfully,
A+1
A+2
A+3
7
Memory
B0
B1
B2
B3
0
lsbyte
msbyte
31
B3
24 23
B2
Register
16 15
B1
8 7
B0
0
SAM3S
61

Related parts for SAM3S1B