ATSAM3S4AA-MU Atmel, ATSAM3S4AA-MU Datasheet - Page 60

• 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

10.5.5.1
10.5.5.2
10.5.6
60
SAM3S Preliminary
Memory endianness
Directly accessing an alias region
Directly accessing a bit-band region
Figure 10-2. Bit-band mapping
Writing to a word in the alias region updates a single bit in the bit-band region.
Bit[0] of the value written to a word in the alias region determines the value written to the tar-
geted bit in the bit-band region. Writing a value with bit[0] set to 1 writes a 1 to the bit-band bit,
and writing a value with bit[0] set to 0 writes a 0 to the bit-band bit.
Bits[31:1] of the alias word have no effect on the bit-band bit. Writing 0x01 has the same effect as
writing 0xFF. Writing 0x00 has the same effect as writing 0x0E.
Reading a word in the alias region:
“Behavior of memory accesses” on page 56
word accesses to the bit-band regions.
The processor views memory as a linear collection of bytes numbered in ascending order from
zero. For example, bytes 0-3 hold the first stored word, and bytes 4-7 hold the second stored
word. or
• 0x00000000 indicates that the targeted bit in the bit-band region is set to zero
• 0x00000001 indicates that the targeted bit in the bit-band region is set to 1
7
7
0x23FFFFFC
0x2200001C
6
6
“Little-endian format”
5
5
0x200FFFFF
0x20000003
4
4
3
3
0x23FFFFF8
0x22000018
2
2
1
1
0
0
7
7
0x23FFFFF4
0x22000014
6
6
describes how words of data are stored in memory.
5
5
0x200FFFFE
0x20000002
4
4
1MB SRAM bit-band region
3
3
0x23FFFFF0
0x22000010
32MB alias region
2
2
1
1
0
0
describes the behavior of direct byte, halfword, or
7
7
0x23FFFFEC
0x2200000C
6
6
5
5
0x200FFFFD
0x20000001
4
4
3
3
0x23FFFFE8
0x22000008
2
2
1
1
0
0
7
7
0x23FFFFE4
0x22000004
6
6
5
5
0x200FFFFC
0x20000000
4
4
6500C–ATARM–8-Feb-11
3
3
0x23FFFFE0
0x22000000
2
2
1
1
0
0