Z86D990 Datasheet, PDF (48/102 Pages) Zilog, Inc. – Low-Voltage Micro controllers with ADC

Z86D990/Z86D991 OTP and Z86L99X ROM
Low-Voltage Microcontrollers with ADC
41
+2
IRQ5 (T1 end-of-count)
P5₆
T_OUT
Figure 26. Counter/Timer Output Using T_OUT
The internal clock can be selected as output instead of T₁ by setting TMR bits D₇
and D₆ both to 1. The internal clock (XTAL frequency/2) is then directly output on
P5₆ (Figure 27).
Internal clock
OSC
+2
P5₆
T_OUT
TMR
TMR
Figure 27. Internal Clock Output Using T_OUT
While programmed as T_OUT, P5₆ cannot be modified by a write to port register P5.
However, the Z8 software can examine P5₆’s current output by reading the port
register.
T_IN Modes
The Timer Mode register TMR (F1h) (Figure 28) is used in conjunction with the
Prescaler register PRE₁ (F3h) (Figure 29) to configure P5₂ as T_IN. T_IN is used in
conjunction with T₁ in one of four modes:
• External clock input
• Gated internal clock
• Triggered internal clock
• Retriggerable internal clock
PS003807-1002
PRELIMINARY