Analog Devices ADSP-BF506F Hardware Reference Manual page 469

different setting for each of the first three timer periods after the timer is
enabled, the procedure to follow is:
1. Program the first set of register values.
2. Enable the timer.
3. Immediately program the second set of register values.
4. Wait for the first timer interrupt.
5. Program the third set of register values.
Each new setting is then programmed when a timer interrupt is received.

In
PWM_OUT
there may not be enough time between updates from the buffer
registers to write both the
TIMER_WIDTH
one new value. In order to prevent "pulse width
write the
when decreasing the values, and write the
before the
Timer Period Register (TIMER_PERIOD)
31 30 29 28 27 26
0 0 0 0
15 14 13 12 11 10
0 0 0 0
Figure 10-21. Timer Period Register
ADSP-BF50x Blackfin Processor Hardware Reference
mode with very small periods (less than 10 counts),
register. The next period may use one old value and
register before the
TIMER_WIDTH
register when increasing the value.
TIMER_WIDTH
25 24 23 22 21 20 19 18 17 16
0 0 0 0 0 0 0 0
9 8 7 6 5 4
0 0 0 0 0 0 0 0
General-Purpose Timers
register and the
TIMER_PERIOD
TIMER_PERIOD
TIMER_PERIOD
Reset = 0x0000 0000
0 0 0 0
Timer Period[31:16]
3 2 1 0
0 0 0 0
Timer Period[15:0]

period" errors,
register
register
10-45