Rainbow Electronics ATAR862-3 - Manual (Page 51)

51
ATAR862-3
4556B–4BMCU–02/03
Duty Cycle Generator The duty cycle generator generates duty cycles of 25%, 33% or 50%. The frequency at
the duty cycle generator output depends on the duty cycle and the Timer 2 prescaler
setting. The DCG-stage can also be used as additional programmable prescaler for
Timer 2.
Figure 50. DCG Output Signals
T2MS1 T imer 2 M ode S elect bit 1
T2MS0 T imer 2 M ode S elect bit 0
Mode T2MS1 T2MS0 Clock Output (POUT) Timer 2 Modes
1 1 1 4-bit counter overflow (OVF1) 12-bit compare counter; the
DCG has to be bypassed in
this mode
2 1 0 4-bit compare output (CM1) 8-bit compare counter with 4-
bit programmable prescaler
and duty cycle generator
3 0 1 4-bit compare output (CM1) 8-bit compare counter clocked
by SYSCL or the external clock
input T2I, 4-bit prescaler run,
the counter 2/1 starts after
writing mode 3
4 0 0 4-bit compare output (CM1) 8-bit compare counter clocked
by SYSCL or the external clock
input T2I, 4-bit prescaler stop
and resets
DCGIN
DCGO0
DCGO1
DCGO2
DCGO3