Z86D99 ZILOG [Zilog, Inc.], Z86D99 Datasheet - Page 47

• Manufacturer Part Number: Z86D99
• Description: Low-Voltage Micro controllers with ADC
• Manufacturer: ZILOG [Zilog, Inc.]

PS003807-1002
The time interval (i) until end-of-count, is given by
where t is 8 divided by XTAL frequency, p is the prescaler value (1 – 64), and v is
the counter/timer value (1 – 256). The prescaler and counter/timer are true divide-
by-n counters.
T
The Timer Mode register TMR (
Port 5 Mode register P5M to configure P5
function, P5
is controlled by one of the counter/timers (T
Figure 25. Timer Mode Register T
The P5
and D
ting TMR bits D
T
At end-of-count, the interrupt request line IRQ
put of this flip-flop drives the T
reaches its end-of-count, T
example, the counter/timer is in continuous counting mode, T
cycle output. You can control the duty cycle by varying the initial values after each
end-of-count.
OUT
OUT
D
7
i = t x p x v
Modes
is initialized to a logic 1 whenever the TMR Load bit D
6
D
6
to 1 and 0 , respectively. The counter/timer T
6
output is selected by TMR bits D
6
must be defined as an output line by setting P5M bit D
7
and D
P
R
6
both to
E
D
OUT
2
L
Timer Mode Register
OUT
toggles to its opposite state (see Figure 26). If, for
F1h
(
I
0
OUT
F1h
, freeing P3
line P5
M
) (Figure 25) is used in conjunction with the
R241 TMR
; Read/Write)
Z86D990/Z86D991 OTP and Z86L99X ROM
Operation
I
Low-Voltage Microcontrollers with ADC
6
7
6
N
for T
. In all cases, when the counter/timer
and D
0
or T
A
6
5
0 = No function
1 = Load T
T
T
Reserved = 01
T
Internal clock out = 11
to be a data output line.
OUT
clocks a toggle flip-flop. The out-
OUT
OUT
1
R
6
1
out = 10
) or the internal clock.
. T
operation. In order for T
OUT
modes
off = 00
Y
1
is selected by setting D
mode is turned off by set-
1
2
OUT
is set to 1 .
has a 50% duty
6
to
0
. Output
OUT
7
to
40