ADSP-BF537 Blackfin Processor Hardware Reference
19-49
System Reset and Booting
In SPI slave mode the
HWAIT
functionality must be activated. The
HWAIT
handshake signal can operate on any GPIO pin of port F, G or H. The
resistor shown in
programs
HWAIT
to hold off
the host when high. See
“Host Wait Feedback Strobe (HWAIT)” on
for further details. The SPI module does not provide
extremely large receive FIFOs, so the host is requested to test the
HWAIT
signal at every byte.
Below are timing diagrams of an SPI slave mode boot using an
ADSP-BF536 processor as the host and an ADSP-BF537 processor as the
slave SPI device. On the host side,
PF4
is used as the
CS
which is connected
to the
SPISS
of the slave ADSP-BF537. The SPI slave’s
PG0
(ADSP-BF537 processor) functions as
HWAIT
and connects to
PG1
of the
host (ADSP-BF536 processor). All the timing diagrams are from the SPI
slave point of view.
The loader file used (
SPI_Slave_HostFile.ldr
) is the same one as in
, except two more blocks are added to show
the functionality of this boot mode—a ZEROFILL block going to loca-
tion 0xFFA0 0300 with a byte count of 0x4000 and a data block going to
Figure 19-22. Connections Between Host (SPI Master) and Blackfin Pro-
cessor (SPI Slave)
(MASTER SPI DEVICE)
ADSP-BF534/BF536/BF537
SPICLK
SPICLK
S_SEL
SPISS
MOSI
MOSI
HOST
(SLAVE SPI DEVICE)
MISO
MISO
HWAIT
FLAG/INTERRUPT
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 ...