12.1.4.7.4 SPI Flash Boot
Two types of SPI Flash are supported: SPI Serial Flash and SPI DataFlash.
The SPI Flash bootloader tries to boot on SPI0, first looking for SPI Serial Flash, and then for SPI DataFlash.
It uses only one valid code detection: analysis of Arm exception vectors.
The SPI Flash read is done by means of a Continuous Read command from the address 0x0. This command is 0xE8 for DataFlash devices and 0x0B for Serial Flash devices.
Supported DataFlash Devices
The SPI Flash Boot program supports the DataFlash devices listed in the following table.
| Device | Density | Page Size (bytes) | Number of Pages |
|---|---|---|---|
| AT45DB011 | 1 Mbit | 264 | 512 |
| AT45DB021 | 2 Mbits | 264 | 1024 |
| AT45DB041 | 4 Mbits | 264 | 2048 |
| AT45DB081 | 8 Mbits | 264 | 4096 |
| AT45DB161 | 16 Mbits | 528 | 4096 |
| AT45DB321 | 32 Mbits | 528 | 8192 |
| AT45DB642 | 64 Mbits | 1056 | 8192 |
| AT45DB641 | 64 Mbits | 264 | 37768 |
Supported Serial Flash Devices
The SPI Flash Boot program supports all SPI Serial Flash devices responding correctly to both Get Status and Continuous Read commands.