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Raspberry , , , , :
Broadcom BCM2835 (CPU & GPU);
256/512MB SDRAM;
1/2 USB 2.0 Ports;
None/Ethernet Port;
HDMI;
Audio;
SD Card Slot;
Micro USB for power.
. 2.Raspberry Pi : A, B, B+, 2 B, Zero 3B. ARM11 BroadcomBCM2835 700 256/512, package-on-package . 2 B 4 Cortex-A7 1 1. A USB 2.0, B , B+ 2 B . B, B+ 2 B Ethernet. , BCM2835 OpenGLES 2.0, FullHD- DSP-. .
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RCA HDMI-. B+ 2B 3,5. , SD,MMC, microSD ( B+) SDIO.
Raspberry Pi GPIO. . B 26-, B+ 2 B 40- GPIO.
2. RaspberryPi
Raspberry , 3.
ARM11J6JZF-S (ARM11 Family)
ARMv6 Architecture
Single Core
32-Bit RISC
700 MHz Clock Rate
8 Pipeline Stages
Branch Prediction
ARM1176, , , , , , , 1 . ARM1176JZ-S ARMTrustZone ARMJazelle Java. ARM9 , AMBA 3 AXITM . DVFS ARM11TM [2].
3. ARM 1176
Raspberry RISC.RISC ( ) , , , . RISC- . ( ).RISC (ReducedInstructionSetComputer), . . .
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SPI /, SPI.
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1 ( 1.4) BCM2835.MMUARM(memorymanagementunit ), BCM2835MMU ARM . 4 , . , .
Addresses in ARM Linux are: issued as virtual addresses by the ARM core, then mapped into a physical address by the ARM MMU, then mapped into a bus address by the ARM mapping MMU, and finally used to select the appropriate peripheral or location in RAM.
, ARMLinux, [4]:
ARM,
ARMMMU,
ARMMMU, , ,
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, BCM2835 Linux . 1GB / 3GB .
0xC0000000 0xEFFFFFFF.
(.. , ARM Linux) 0x00000000 0xbfffffff.
( 0x20000000) , 0xF2000000. , 0x7Ennnnnn ARM 0xF2nnnnnn.
4. BCM2835
. , DMA, . ( 0x00000000). DMA ( 0xC0000000).
BCM2835 bus , . DMA -- . , DMA , , L2 .
DMA BCM2835 16 DMA. 3- . DMA .
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, : (Core), (LoadStoreUnit), (PrefetchUnit), (MMU), 1 2 , (InterruptHanding), AMBA , , TCM, (Debug), (VectorFloatingPoint), (. 5).
5. [4]
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, . , CPU , ( x86 CPU IntelPentium II Pentium III Slot 1, AMD Athlon Slot A L2- 1/2, 1/3 ). L3 , , . , . .
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-, , . , ӻ. , , . CPU. : 10'000 , 1000 . , , , ? 1000 , CPU : , . , : , , , CPU .
http://www.ixbt.com/cpu/cpu-digest-2009.shtml