ADSP-BF535 Blackfin Processor Hardware Reference
10-35
SPI Compatible Port Controllers
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
SPIx_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
SPIx_RDBR
. If
GM = 0
and the receive buffer is full, the incoming data is
discarded, and
SPIx_RDBR
is not updated.
Slave Ready for a Transfer
Table 10-20
shows the actions necessary to prepare the device for a new
transfer, when a device is enabled as a slave.
Error Signals and Flags
The status of a device is indicated by the
SPIx_ST
register. See
“SPIx Sta-
tus Register (SPIx_ST)” on page 10-15
for more information.
Table 10-20. Transfer Preparation
TIMOD
Function
Action, Interrupt
00
Transmit and
Receive
Interrupt active when receive buffer is full
Read of SPIx_RDBR clears interrupt
01
Transmit and
Receive
Interrupt active when transmit buffer is empty
Writing to SPIx_TDBR clears interrupt
10
Transmit or
Receive with
DMA
Interrupt configured in SPIx_CONFIG
Interrupt active upon DMA error or multiword transfer com-
plete
Writing 1 to SPI_DMA_INT clears interrupt
11
Reserved
N/A
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...