AT91SAM9261SB-CU-999 Atmel, AT91SAM9261SB-CU-999 Datasheet - Page 49

• Manufacturer Part Number: AT91SAM9261SB-CU-999
• Description: IC MCU ARM9 ULTRA LP 217LFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9261SB-CU-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 190MHz
• Connectivity: EBI/EMI, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: DMA, LCD, POR, PWM, WDT
• Number Of I /o: 96
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.08 V ~ 1.32 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 217-LFBGA
• Processor Series: AT91SAMx
• Core: ARM926EJ-S
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: 2-Wire, I2S, SPI, USB
• Maximum Clock Frequency: 190 MHz
• Number Of Programmable I/os: 96
• Number Of Timers: 4
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM9261-EK
• Minimum Operating Temperature: - 40 C
• For Use With: AT91SAM9261-EK - KIT EVAL FOR AT91SAM926EJ-SAT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

11.4.2
11.4.3
11.4.4
6242E–ATARM–11-Sep09
Translation Look-aside Buffer (TLB)
Translation Table Walk Hardware
MMU Faults
The Translation Look-aside Buffer (TLB) caches translated entries and thus avoids going
through the translation process every time. When the TLB contains an entry for the MVA (Modi-
fied Virtual Address), the access control logic determines if the access is permitted and outputs
the appropriate physical address corresponding to the MVA. If access is not permitted, the MMU
signals the CPU core to abort.
If the TLB does not contain an entry for the MVA, the translation table walk hardware is invoked
to retrieve the translation information from the translation table in physical memory.
The translation table walk hardware is a logic that traverses the translation tables located in
physical memory, gets the physical address and access permissions and updates the TLB.
The number of stages in the hardware table walking is one or two depending whether the
address is marked as a section-mapped access or a page-mapped access.
There are three sizes of page-mapped accesses and one size of section-mapped access. Page-
mapped accesses are for large pages, small pages and tiny pages. The translation process
always begins with a level one fetch. A section-mapped access requires only a level one fetch,
but a page-mapped access requires an additional level two fetch. For further details on the
MMU, please refer to chapter 3 in ARM926EJ-S Technical Reference Manual, ref. DDI0198B.
The MMU generates an abort on the following types of faults:
The access control mechanism of the MMU detects the conditions that produce these faults. If
the fault is a result of memory access, the MMU aborts the access and signals the fault to the
CPU core.The MMU retains status and address information about faults generated by the data
accesses in the data fault status register and fault address register. It also retains the status of
faults generated by instruction fetches in the instruction fault status register.
The fault status register (register 5 in CP15) indicates the cause of a data or prefetch abort, and
the domain number of the aborted access when it happens. The fault address register (register 6
in CP15) holds the MVA associated with the access that caused the Data Abort. For further
details on MMU faults, please refer to chapter 3 in ARM926EJ-S Technical Reference Manual,
ref. DDI0198B.
• Alignment faults (for data accesses only)
• Translation faults
• Domain faults
• Permission faults
AT91SAM9261S
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