3 dataflash boot sequence – Rainbow Electronics AT91CAP9S250A User Manual

Page 77

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77

6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

Figure 14-5. Structure of the ARM Vector 6

14.4.2.1

Example

An example of valid vectors follows:

00

ea000006

B

0x20

04

eafffffe

B

0x04

08

ea00002f

B

_main

0c

eafffffe

B

0x0c

10

eafffffe

B

0x10

14

00001234

B

0x14

<- Code size = 4660 bytes

18

eafffffe

B

0x18

The size of the image to load into SRAM is contained in the location of the sixth ARM vector.
Thus the user must replace this vector by the correct vector for his application.

14.4.3

DataFlash Boot Sequence

The DataFlash Boot program performs device initialization followed by the download
procedure.

The DataFlash Boot program supports all Atmel DataFlash devices.

Table 14-2

summarizes

the parameters to include in the ARM vector 6 for all devices.

The DataFlash has a Status Register that determines all the parameters required to access
the device. The DataFlash Boot is configured to be compatible with the future design of the
DataFlash.

31

0

Size of the code to download in bytes

Table 14-2.

DataFlash Device

Device

Density

Page Size (bytes)

Number of Pages

AT45DB011B

1 Mbit

264

512

AT45DB021B

2 Mbits

264

1024

AT45DB041B

4 Mbits

264

2048

AT45DB081B

8 Mbits

264

4096

AT45DB161B

16 Mbits

528

4096

AT45DB321B

32 Mbits

528

8192

AT45DB642

64 Mbits

1056

8192

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