1. SOC Design Lecture 4
Bus and AMBA Introduction

2. Road without Traffic Lights

3. Communication between Multiples

4. Bus
bus

5. Two Types of Connections
Register
Register
Register
Register
화면 내 공간적 유사성을 보여주는 그림 삽입 필요
Register
Register
Register
Register
Register
Register
Point-to-Point Connection
Common Bus-based Connection

6. Bus
A subsystem that transfers data or signals between digital components .
Unlike a point-to-point connection, a bus can connect multiple components over the same set of wires.
Each bus defines its set of signals to physically connect components together.
The definition of the signals implicitly include the protocols on how to use the signals.

7. First Generation Bus
A bundles of wires connected to CPU pins directly.
Memory and other devices are added to the bus using the same address and data pins as the CPU itself in parallel.
Drawbacks
All component must have same clock -> limited clock frequency
CPU is busy due to heavy bus transactions. -> low throughput.
Examples : Early IBM PCs in 1980s.

8. Second Generation Bus
Separated the system into two "worlds", the CPU and memory on one side, and the various devices on the other, with a bus controller in between.
CPU can now be free from slow peripheral bottleneck.
Shortcomings
A lot of bus controllers (for each slot in a computer.)
Examples : SCSI, IDE

9. Widely Known Buses Parallel Serial
Industry Standard Architecture or ISA
Advanced Technology Attachment or ATA (aka PATA, IDE, EIDE, ATAPI, etc.) disk peripheral attachment bus
Peripheral Component Interconnect or PCI
PC card, previously known as PCMCIA,
SCSI Small Computer System Interface (disk peripheral attachment)
Serial
1-Wire
HyperTransport
I²C
PCI Express or PCIe
Serial Peripheral Interface Bus or SPI bus
USB Universal Serial Bus

10. Bus for SOC SOC needs a bus, of course. SOC bus should support
Modular system design
Technology-independence
Easy to use
Light in size and complexity

11. AMBA Stands for Advanced Microcontroller Bus Architecture
Developed by ARM in 1990s (England)
ARM also developed ARM RISC series for SOC applications.
ARM is now the mostly widely used RISC core and that makes AMBA most popular BUS in SOC world.

12. Typical AMBA System
ASB is not used these days.

13. Key AMBA Version
AMBA 2.0 : AHB, APB, ASB
AMBA 3.0 : AXI

14. HW #1 (Due in next class)
Visit ww.arm.com and search AMBA specifications.
For AHB and AXI respectively, find out the followings and submit them in a report.
Years they are made.
The number of signals.