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Specific Boot Modes
24-54
ADSP-BF50x Blackfin Processor Hardware Reference
The external frame sync signal is on
PPI_FS1
. This signal is driven low by
the host at the start of a data transfer with a 16-bit word being transferred
on each
PPI_CLK
cycle that the
PPI_FS1
signal is asserted low.
In order to simplify the PPI host design, PPI boot mode also configures
Timer1 for PWM mode of operation. The PWM circuits of the timer are
configured to be clocked by the externally provided
PPI_CLK
signal allow-
ing for arbitrary pulse widths and pulse periods to be programmed thus
simulating an internally generated frame sync signal on the
PPI_FS2
signal.
This configuration lets the processor inform the host when the processor is
ready to receive data and also how much data is expected. This feature
removes the need for the host to process the actual contents of the boot
stream to identify the size of the data transfer.
The PPI host can synchronize the
PPI_FS2
signal to
PPI_CLK
signal and
initiate all data transfers accordingly. The
PPI_FS2
signal can be looped
back to the
PPI_FS1
. (See
Figure 24-16
.)
The Timer1 is configured to generate a periodic pulse as opposed to a sin-
gle shot pulse. The pulse period is set to the maximum of 0xFFFFFFFF
allowing for any transfer size supported by the kernel. Note the current
Figure 24-16. PPI Slave Boot Mode Connections
(MASTER PPI DEVICE)
BLACKFIN
PPI_CLK
PPI_CLK
HOST
(SLAVE PPI DEVICE)
PPI_FS1
PPI_FS1
PPI_FS2
PPI_FS2
PPI_DATA15-0
PPI_DATA15-0
VDDEXT
16
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 ...