ADSP-BF537 Blackfin Processor Hardware Reference
19-45
System Reset and Booting
processor, the on-chip boot ROM sends the following sequence of bytes to
the SPI memory until the memory responds back. The SPI memory does
not respond back until it is properly addressed. The on-chip boot ROM:
1. Sends the read command, 0x03, on the
MOSI
pin then does a
dummy read of the
MISO
pin.
2. Sends an address byte, 0x00, on the
MOSI
pin then does a dummy
read of the
MISO
pin.
3. Sends another byte, 0x00, on the
MOSI
pin and checks whether the
incoming byte on the
MISO
pin is anything other than 0xFF (value
from the pull-up resistor). An incoming byte that is not 0xFF
means that the SPI memory has responded back after one address
byte and an 8-bit addressable SPI memory device is assumed to be
connected.
4. If the incoming byte is 0xFF, the on-chip boot ROM sends another
byte, 0x00, on the
MOSI
pin and checks whether the incoming byte
on the
MISO
pin is anything other than 0xFF. An incoming byte
other than 0xFF means that the SPI memory has responded back
after two address bytes and a 16-bit addressable SPI memory device
is assumed to be connected.
5. If the incoming byte is 0xFF, the on-chip boot ROM sends another
byte, 0x00, on the
MOSI
pin and checks whether the incoming byte
on the
MISO
pin is anything other than 0xFF. An incoming byte
other than 0xFF means that the SPI memory has responded back
after three address bytes and a 24-bit addressable SPI memory
device is assumed to be connected.
6. If an incoming byte is 0xFF (meaning no devices have responded
back), the on-chip boot ROM assumes that one of these Atmel
DataFlash devices is connected: AT45DB041B, AT45DB081B,
AT45DB161B, AT45DB321, AT45DB642 or AT45DB1282.
These DataFlash devices have a different read sequence than the
one described above for standard SPI memories. For more
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...