Z86L972 Datasheet, PDF (43/91 Pages) Zilog, Inc. – Low-Voltage Microcontrollers

Z86L972/Z86L973/Z86L974
Low-Voltage Microcontrollers
36
+2
IRQ5 (T1 end-of-count)
P5₆
T_OUT
Figure 23. 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 24).
Internal clock
OSC
+2
P5₆
T_OUT
TMR
TMR
Figure 24. 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 25) is used in conjunction with the
Prescaler register PRE₁ (F3h) (Figure 26) 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
PS010504-1002
PRELIMINARY