ADSP-BF537 Blackfin Processor Hardware Reference
15-31
General-Purpose Timers
(because no measurement report occurred to copy the value captured in
the width buffer register to
TIMERx_WIDTH
). See the first interrupt in
.
L
When using the
PERIOD_CNT
=
0
mode described above to measure
the width of a single pulse, it is recommended to disable the timer
after taking the interrupt that ends the measurement interval. If
desired, the timer can then be reenabled as appropriate in prepara-
tion for another measurement. This procedure prevents the timer
from free-running after the width measurement and logging errors
generated by the timer count overflowing.
A timer interrupt (if enabled) is generated if the timer counter register
wraps around from 0xFFFF FFFF to 0 in the absence of a leading edge. At
that point, the
TOVF_ERRx
bit in the
TIMER_STATUS
register and the
ERR_TYP
bits in the
TIMERx_CONFIG
register are set, indicating a count overflow due
to a period greater than the counter’s range. This is called an error report.
When a timer generates an interrupt in
WDTH_CAP
mode, either an error has
occurred (an error report) or a new measurement is ready to be read (a
measurement report), but never both at the same time. The
TIMERx_PERIOD
and
TIMERx_WIDTH
registers are never updated at the time
an error is signaled. Refer to
and
for more
information.
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 ...