ADSP-BF50x Blackfin Processor Hardware Reference
18-19
SPI-Compatible Port Controller
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
zeros on the
MOSI
pin. One word is transmitted for each new transfer initi-
ate command. If
SZ
= 0 and the transmit buffer is empty, the device
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
MISO
pin, overwriting the older data in the
SPI_RDBR
regis-
ter. If
GM
= 0 and the receive buffer is full, the incoming data is discarded,
and
SPI_RDBR
is not updated.
Transfer Initiation From Master (Transfer Modes)
When a device is enabled as a master, the initiation of a transfer is defined
by the two TIMOD bits of SPI_CTL. Based on those two bits and the sta-
tus of the interface, a new transfer is started upon either a read of the
SPI_RDBR register or a write to the SPI_TDBR register. This is summa-
rized in
Table 18-1
.
If the SPI port is enabled with
TIMOD
=
b#01
or
TIMOD
=
b#11
, the
hardware immediately issues a first interrupt or DMA request.
Содержание EZ-KIT Lite ADSP-BF506F
Страница 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 132: ...Unique Information for the ADSP BF50x Processor 4 22 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 342: ...Unique Information for the ADSP BF50x Processor 7 106 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 484: ...Unique Information for the ADSP BF50x Processor 10 60 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 493: ...ADSP BF50x Blackfin Processor Hardware Reference 11 9 Core Timer Unique Information for the ADSP BF50x Processor None ...
Страница 494: ...Unique Information for the ADSP BF50x Processor 11 10 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 506: ...Unique Information for the ADSP BF50x Processor 12 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 544: ...Unique Information for the ADSP BF50x Processor 13 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 712: ...Unique Information for the ADSP BF50x Processor 16 62 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 972: ...Unique Information for the ADSP BF50x Processor 20 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...