Data Delays, Latencies and Throughput
25-4
ADSP-BF50x Blackfin Processor Hardware Reference
Listing 25-1. Query Semaphore
/* Query semaphore. Denotes “Busy” if its value is nonzero. Wait
until free (or reschedule thread-- see note below). P0 holds
address of semaphore. */
QUERY:
TESTSET ( P0 ) ;
IF !CC JUMP QUERY ;
/* At this point, semaphore has been granted to current thread,
and all other contending threads are postponed because semaphore
value at [P0] is nonzero. Current thread could write thread_id to
semaphore location to indicate current owner of resource. */
R0.L = THREAD_ID ;
B[P0] = R0 ;
/* When done using shared resource, write a zero byte to [P0] */
R0 = 0 ;
B[P0] = R0 ;
SSYNC ;
/* NOTE: Instead of busy idling in the QUERY loop, one can use an
operating system call to reschedule the current thread. */
Data Delays, Latencies and Throughput
For detailed information on latencies and performance estimates on the
DMA and external memory buses, refer to the
Chip Bus Hierarchy
chapter.
Bus Priorities
For an explanation of prioritization between the various internal buses,
refer to the
Chip Bus Hierarchy
chapter.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...