Analog Devices ADSP-BF506F Hardware Reference Manual page 468

Timer Registers
Usage of the
TIMER_PERIOD
register, shown in
TIMER_WIDTH
mode of the timer:
• In PWM_OUT mode, both the TIMER_PERIOD and
TIMER_WIDTH register values can be updated "on-the-fly" since
the values change simultaneously.
• In WDTH_CAP mode, the timer period and timer pulse width
buffer values are captured at the appropriate time. The
TIMER_PERIOD and TIMER_WIDTH registers are then
updated simultaneously from their respective buffers. Both regis-
ters are read-only in this mode.
• In EXT_CLK mode, the TIMER_PERIOD register is writable and
can be updated "on-the-fly." The TIMER_WIDTH register is not
used.
If new values are not written to the
register, the value from the previous period is reused. Writes
TIMER_WIDTH
to the 32-bit
TIMER_PERIOD
is not possible for the high word to be written without the low word also
being written.
Values written to the
always stored in the buffer registers. Reads from the
registers always return the current, active value of period or
TIMER_WIDTH
pulse width. Written values are not read back until they become active.
When the timer is enabled, they do not become active until after the
TIMER_PERIOD
buffers at the end of the current period. See
When the timer is disabled, writes to the buffer registers are immediately
copied through to the
will be ready for use in the first timer period. For example, to change the
values for the
TIMER_PERIOD
10-44
register, shown in
Figure
register and
TIMER_PERIOD
and registers are updated from their respective
TIMER_WIDTH
TIMER_PERIOD
and/or
ADSP-BF50x Blackfin Processor Hardware Reference
Figure 10-21, and the
10-22, varies depending on the
register or the
TIMER_PERIOD
register are atomic; it
TIMER_WIDTH
registers or
TIMER_WIDTH
TIMER_PERIOD
Figure 10-1 on page
or register so that they
TIMER_WIDTH
registers in order to use a
TIMER_WIDTH
registers are
or
10-3.