技 术 报 告
名 称: AMBA 协议 2.0 详细研究
编 号:
版本号: 0.2
作 者 余华新
项 目 Zi209
部 门 产品中心
日 期 2006-09-08
深圳市中兴集成电路设计有限责任公司
中文标题
Title
摘 要:
关键词:
Abstract:
Key Words:
目 录
1 AMBA总线概述......................................................................................................................................................... 7
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
AMBA标准概述........................................................................................................................................ 7
定义AMBA标准的目的........................................................................................................................... 7
一个典型的基于AMBA总线的SOC系统架构..................................................................................... 7
术语............................................................................................................................................................. 8
AHB介绍.................................................................................................................................................... 8
ASB介绍(忽略).......................................................................................................................................... 9
APB介绍..................................................................................................................................................... 9
选择正确的系统总线 ............................................................................................................................... 9
协议注意................................................................................................................................................... 10
2 AMBA信号................................................................................................................................................................ 10
2.1
2.2
2.3
AHB信号列表...........................................................................................................................................11
ASB信号列表(忽略)............................................................................................................................... 12
APB信号列表.......................................................................................................................................... 13
3 AHB总线.................................................................................................................................................................... 14
3.1
什么是AHB总线?................................................................................................................................. 14
3.1.1
一个典型的基于AHB总线的微控制器架构.............................................................................. 15
3.2
3.3
3.4
3.5
3.6
3.4.1
3.4.2
3.4.3
3.6.1
3.6.2
AHB总线互连结构................................................................................................................................. 17
AHB操作概述.......................................................................................................................................... 18
基本传输................................................................................................................................................... 19
零等待传输(no wait state transfer)................................................................................................ 19
等待传输(transfers with wait states)) ............................................................................................ 20
多重传送(multiple transfer) ........................................................................................................... 20
控制信号:传送状态HTRANS[1:0].................................................................................................... 22
控制信号:批量传送HBURST[2:0] .................................................................................................... 24
提前结束Burst(参 3.11) ................................................................................................................. 24
长度为 4 的回绕地址传送方式(four-beat wrapping burst)。................................................ 25
1
3.6.3
3.6.4
长度为 4 的递增地址传送方式(Incrementing burst of length 4) ........................................ 25
不限长度的传送方式..................................................................................................................... 26
3.7
控制信号:其它...................................................................................................................................... 27
3.8
3.9
3.7.1
3.7.2
3.7.3
3.9.1
3.9.2
3.9.3
3.9.4
3.9.5
传送方向HWRITE......................................................................................................................... 27
传送大小HSIZE[2:0]...................................................................................................................... 27
保护控制HPROT[3:0].................................................................................................................... 27
地址译码................................................................................................................................................... 29
从传输应答.............................................................................................................................................. 30
传送完成HREADY........................................................................................................................ 30
其它从传输应答HRESP[1:0]........................................................................................................ 30
两周期应答(Two-cycle response) ................................................................................................. 31
错误应答Error................................................................................................................................. 31
分段传送与重传的异同................................................................................................................ 32
3.10
数据总线................................................................................................................................................... 34
3.10.1
HWDATA[31:0].............................................................................................................................. 34
3.10.2
HRDATA[31:0] ............................................................................................................................... 34
3.10.3 位格式Endianness........................................................................................................................... 34
3.11
总线仲裁机制(重点)............................................................................................................................... 35
3.11.1 信号描述.......................................................................................................................................... 35
3.11.2 总线访问请求................................................................................................................................. 35
3.11.3 总线访问批准................................................................................................................................. 36
3.11.4 提前结束Burst................................................................................................................................. 39
3.11.5 锁定传送Locked transfers.............................................................................................................. 39
3.11.6 预设总线主设备............................................................................................................................. 40
3.12
分段传送HSPLITx(重点)....................................................................................................................... 41
3.12.1 分段传送顺序................................................................................................................................. 41
3.12.2 多重分段传送(multiple split transfers)......................................................................................... 41
3.12.3 防死锁/ 锁住避免(deadlock prevention)..................................................................................... 41
2
3.12.4 分段传送之总线转换..................................................................................................................... 42
3.13
3.14
3.15
3.16
复位机制HRESETn ................................................................................................................................ 44
数据总线位宽HSIZE[2:0]...................................................................................................................... 44
宽总线-窄从Implementing a narrow S on a wider bus......................................................................... 44
窄总线-宽从Implementing a wide S on a narrow bus.......................................................................... 44
3.16.1 Ms..................................................................................................................................................... 44
3.17
3.18
AHB组件.................................................................................................................................................. 45
AHB从(重点)........................................................................................................................................... 45
3.18.1 从接口框图 ..................................................................................................................................... 45
3.18.2 从时序.............................................................................................................................................. 46
3.19
AHB主(重点)........................................................................................................................................... 47
3.19.1 主接口框图 ..................................................................................................................................... 47
3.19.2 主时序.............................................................................................................................................. 48
3.20
仲裁器(arbiter) ......................................................................................................................................... 50
3.20.1 接口框图.......................................................................................................................................... 50
3.20.2 时序.................................................................................................................................................. 50
3.21
译码器(decoder)....................................................................................................................................... 52
3.21.1 接口框图.......................................................................................................................................... 52
3.21.2 时序.................................................................................................................................................. 52
4 ASB总线(未实用,忽略)............................................................................................................................................ 53
5 APB总线 .................................................................................................................................................................... 54
5.1
什么是APB总线?.................................................................................................................................. 54
5.1.1
一个典型的基于AMBA总线的系统架构 .................................................................................. 54
5.2
APB规范................................................................................................................................................... 54
5.2.1
5.2.2
5.2.3
APB状态机...................................................................................................................................... 55
写操作.............................................................................................................................................. 55
读操作.............................................................................................................................................. 56
5.3
APB组件................................................................................................................................................... 57
3
5.4
APB桥....................................................................................................................................................... 58
5.4.1
5.4.2
5.4.3
5.4.4
接口框图.......................................................................................................................................... 58
描述.................................................................................................................................................. 58
时序.................................................................................................................................................. 59
APB桥(APB主)的时序参数.................................................................................................... 59
5.5
APB从....................................................................................................................................................... 61
5.5.1
5.5.2
5.5.3
5.5.4
接口框图.......................................................................................................................................... 61
描述.................................................................................................................................................. 61
时序.................................................................................................................................................. 62
APB从的时序参数......................................................................................................................... 62
5.6
APB到AHB的接口................................................................................................................................. 63
5.6.1
5.6.2
5.6.3
5.6.4
5.7
5.8
读操作.............................................................................................................................................. 63
写操作.............................................................................................................................................. 65
读写交替传送(Back to back)................................................................................................... 67
三态数据线的实现......................................................................................................................... 68
APB到ASB的接口(忽略)....................................................................................................................... 68
D版本APB到 2.0 版本APB(忽略)........................................................................................................ 68
6 测试方法学................................................................................................................................................................ 69
6.1
6.2
6.3
6.4
6.2.1
6.2.2
6.2.3
6.2.4
6.2.5
AMBA测试接口...................................................................................................................................... 69
外部接口................................................................................................................................................... 70
TREQA............................................................................................................................................ 70
TREQB ............................................................................................................................................ 70
TACK............................................................................................................................................... 70
Test clock.......................................................................................................................................... 71
Test bus............................................................................................................................................. 71
测试向量类型.......................................................................................................................................... 71
测试接口控制器...................................................................................................................................... 72
6.4.1
测试操作参数................................................................................................................................. 72
4
6.4.2
6.4.3
6.4.4
6.4.5
6.4.6
6.4.7
6.4.8
6.4.9
递增寻址.......................................................................................................................................... 72
进入测试模式................................................................................................................................. 73
地址向量.......................................................................................................................................... 73
控制向量.......................................................................................................................................... 74
写操作向量 ..................................................................................................................................... 74
读操作向量 ..................................................................................................................................... 74
批量向量.......................................................................................................................................... 75
改变操作方向................................................................................................................................. 75
6.4.10 退出测试模式................................................................................................................................. 75
6.5
AHB测试接口控制器............................................................................................................................. 75
6.5.1
Control vector .................................................................................................................................. 77
6.6
AHB测试程序举例................................................................................................................................. 78
6.6.1
6.6.2
6.6.3
6.6.4
6.6.5
6.6.6
6.6.7
Entering test mode........................................................................................................................... 78
写操作.............................................................................................................................................. 79
读操作.............................................................................................................................................. 79
控制向量.......................................................................................................................................... 80
批量向量.......................................................................................................................................... 80
交替读写Read-to-write and write-to-read..................................................................................... 81
退出测试模式................................................................................................................................. 81
6.7
6.8
ASB测试接口控制器(忽略) .................................................................................................................. 81
ASB测试程序举例(忽略)....................................................................................................................... 81
7 几个比较..................................................................................................................................................................... 82
7.1
7.2
7.3
7.4
不同总线之比较...................................................................................................................................... 82
AMBA2.0 与AMBA3.0(AXI)................................................................................................................ 82
递增与回绕(参 3.6)................................................................................................................................. 82
重发与分段发送(参 3.9.5)...................................................................................................................... 82
7.5................................................................................................................................................................................. 82
5
Date
Revision History
Revision
2006-09-08
2006-09-14 补充 APB 部分(From 余讯)
Initial version(以 AMBA2.0 协议为蓝本,非纯粹协议翻译)
Versio
n
0.1
0.2
By
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余华新
余华新
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文档阅读指南:
1. 标题 靛蓝色
2. 接口信号名 蓝色
3. 强调 粉红色
4. 主设备 M
5. 从设备 S
6. 表号在表上
7. 图号在图下
6