AT91SAM7X256B-AU Atmel, AT91SAM7X256B-AU Datasheet - Page 94

• Manufacturer Part Number: AT91SAM7X256B-AU
• Description: IC MCU 256KB FLASH 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7X256B-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: CAN, Ethernet, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 55 MHz
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/Ethernet/SPI/I2S/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Number Of Timers: 3
• Controller Family/series: AT91SAM7xxxxx
• No. Of I/o's: 62
• Ram Memory Size: 64KB
• Cpu Speed: 55MHz
• No. Of Timers: 1
• Rohs Compliant: Yes
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 55MHz
• Total Internal Ram Size: 64KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 1.8/3.3V
• Operating Supply Voltage (max): 1.95/3.6V
• Operating Supply Voltage (min): 1.65/3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

18.3
18.3.1
18.3.2
94
Functional Description
AT91SAM7X512/256/128 Preliminary
Bus Arbiter
Address Decoder
The Memory Controller handles the internal ASB bus and arbitrates the accesses of up to three
masters.
It is made up of:
The MC handles only little-endian mode accesses. The masters work in little-endian mode only.
The Memory Controller has a simple, hard-wired priority bus arbiter that gives the control of the
bus to one of the three masters. The EMAC has the highest priority; the Peripheral DMA Control-
ler has the medium priority; the ARM processor has the lowest one.
The Memory Controller features an Address Decoder that first decodes the four highest bits of
the 32-bit address bus and defines three separate areas:
Figure 18-2
Figure 18-2. Memory Areas
• A bus arbiter
• An address decoder
• An abort status
• A misalignment detector
• An Embedded Flash Controller
• One 256-Mbyte address space for the internal memories
• One 256-Mbyte address space reserved for the embedded peripherals
• An undefined address space of 3584M bytes representing fourteen 256-Mbyte areas that
return an Abort if accessed
shows the assignment of the 256-Mbyte memory areas.
14 x 256MBytes
256M Bytes
256M Bytes
3,584 Mbytes
0x0000 0000
0xF000 0000
0x0FFF FFFF
0xEFFF FFFF
0xFFFF FFFF
0x1000 0000
Internal Memories
Peripherals
Undefined
(Abort)
6120H–ATARM–17-Feb-09