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ARM advanced microcontroller bus architecture (AMBA) specification.Rev 2.0.pdf
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AMBA AHB

3.21 AHB decoder

The decoder in an AMBA system is used to perform a centralized address decoding function, which improves the portability of peripherals, by making them independent of the system memory map.

3.21.1Interface diagram

Figure 3-35 shows an AHB decoder.

HSELx1

Address

HADDR[31:0]

AHB

HSELx2

Select

decoder

HSELx3

 

 

 

 

 

 

 

 

Figure 3-35 AHB decoder interface diagram

3.21.2Timing diagram

The timing parameters for an AHB decoder are shown in Figure 3-36.

HCLK

 

HADDR

A

HSELx

 

 

Tadsel

Figure 3-36 AHB decoder timing parameter

3.21.3Timing parameter

The timing parameter related to an AHB decoder is given in Table 3-14.

Table 3-14 AHB decoder output parameter

Parameter Description

Tadsel

Delay from Address to Select valid

ARM IHI 0011A

© Copyright ARM Limited 1999. All rights reserved.

3-57

AMBA AHB

3-58

© Copyright ARM Limited 1999. All rights reserved.

ARM IHI 0011A