Specific Blackfin Boot Modes
19-56
ADSP-BF537 Blackfin Processor Hardware Reference
L
On the Blackfin processor, in both TWI master and slave boot
modes, the upper 256 bytes of data bank A starting at address
0xFF90 3F00 must not be used. The boot ROM code uses this
space for the TWI boot modes to temporarily hold the serial data
which is then transferred to L1 instruction memory using DMA.
UART Slave Mode Boot via Master Host
(BMODE = 111)
UART booting on the Blackfin processor is supported only through
UART0, and the Blackfin processor is always a slave.
Using an autobaud detection sequence, a boot-stream-formatted program
is downloaded by the host. The host agent selects a bit rate within the
UART’s clocking capabilities. When performing the autobaud, the UART
expects an “@” character (0x40, eight bits data, one start bit, one stop bit,
no parity bit) on the UART0
RXD
input to determine the bit rate. The
hardware support and the mathematical operations to perform for this
autobaud detection is explained in
Chapter 15, “General-Purpose Timers”
. The boot kernel then replies with
an acknowledgement, and the host can then download the boot stream.
The acknowledgement consists of the following four bytes:
0xBF
,
UART0_DLL
,
UART0_DLH
,
0x00
. The host is requested to not send further
Figure 19-32. TWI Slave Boot Mode
ADSP-BF537
(SLAVE DEVICE)
I2C-COMPATIBLE HOST
SDA
SDA
SCL
(MASTER DEVICE)
SCL
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 ...