ADSP-BF537 Blackfin Processor Hardware Reference
10-27
SPI Compatible Port Controllers
5. Reception/transmission continues until
SPISS
is released or until
the slave has received the proper number of clock cycles.
6. The slave device continues to receive/transmit with each new fall-
ing edge transition on
SPISS
and/or active
SCK
clock edge.
See
If the transmit buffer remains empty or the receive buffer remains full, the
device operates according to the states of the
SZ
and
GM
bits in
SPI_CTL
. If
SZ = 1
and the transmit buffer is empty, the device repeatedly transmits 0s
on the
MISO
pin. If
SZ = 0
and the transmit buffer is empty, it repeatedly
transmits the last word it transmitted before the transmit buffer became
empty. If
GM = 1
and the receive buffer is full, the device continues to
receive new data from the
MOSI
pin, overwriting the older data in
SPI_RDBR
. If
GM = 0
and the receive buffer is full, the incoming data is dis-
carded, and
SPI_RDBR
is not updated.
Slave Ready for a Transfer
When a device is enabled as a slave, the actions shown in
are
necessary to prepare the device for a new transfer.
Table 10-5. Transfer Preparation
TIMOD
Function
Action, Interrupt
00
Transmit and
Receive
Interrupt active when receive buffer is full.
Read of SPI_RDBR clears interrupt.
01
Transmit and
Receive
Interrupt active when transmit buffer is empty.
Writing to SPI_TDBR clears interrupt.
10
Receive with
DMA
Request DMA reads as long as SPI DMA FIFO is not empty.
11
Transmit with
DMA
Request DMA writes as long as SPI DMA FIFO is not full.
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 ...