Interface Overview
10-6
ADSP-BF537 Blackfin Processor Hardware Reference
The SPI
MISO
signal can connect to the
PF12
pin which functions as a
GPIO by default. To enable this pin for use as the SPI
MISO
signal, be sure
to first configure the
PORTF_FER
register to enable the
PF12
pin for periph-
eral use (see
“Function Enable Registers” on page 14-23
), and then set the
PORT_MUX
register to specifically enable the SPI master out slave in func-
tionality (see
“Port Multiplexer Control Register” on page 14-22
L
Only one slave is allowed to transmit data at any given time.
The SPI configuration example in
illustrates how the proces-
sor can be used as the slave SPI device. The 8-bit host microcontroller is
the SPI master.
L
The processor can be booted via its SPI interface to allow user
application code and data to be downloaded before runtime.
Serial Peripheral Interface Slave Select Input Signal
The
SPISS
signal is the SPI serial peripheral slave select input signal. This
is an active-low signal used to enable a processor when it is configured as a
slave device. This input-only pin behaves like a chip select and is provided
by the master device for the slave devices. For a master device, it can act as
an error signal input in case of the multimaster environment. In multi-
master mode, if the
SPISS
input signal of a master is asserted (driven low),
and the
PSSE
bit in the
SPI_CTL
register is enabled, an error has occurred.
This means that another device is also trying to be the master device.
Figure 10-2. ADSP-BF537 as Slave SPI Device
8-BIT HOST
MICROCONTROLLER
BLACKFIN PROCESSOR
SLAVE SPI DEVICE
SCLK
MOSI
MISO
MISO
SCLK
MOSI
SPISS
S_SEL
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 ...