Z86E30 Zilog., Z86E30 Datasheet - Page 39

• Manufacturer Part Number: Z86E30
• Description: Z8 4K OTP Microcontroller
• Manufacturer: Zilog.

Zilog
The counters can be programmed to start, stop, restart to
continue, or restart from the initial value. The counters can
also be programmed to stop upon reaching zero (single
pass mode) or to automatically reload the initial value and
continue counting (modulo-n continuous mode).
The counters, but not the prescalers, can be read at any
time without disturbing their value or count mode. The
clock source for T1 is user-definable and can be either the
DS97Z8X0500
D0 (SMR)
D1 (SMR)
TIN P31
Clock
Logic
OSC
16
2
External Clock
Internal Clock
Gated Clock
Triggered Clock
Internal
Clock
4
Figure 27. Counter/Timer Block Diagram
4
P R E L I M I N A R Y
Write
Write
Initial Value
Initial Value
Register
Register
Counter
Counter
PRE0
PRE1
Down
Down
6-Bit
6-Bit
internal microprocessor clock divided by four, or an exter-
nal signal input through Port 3. The Timer Mode register
configures the external timer input (P31) as an external
clock, a trigger input that can be retriggerable or non-retrig-
gerable, or as a gate input for the internal clock. Port 3 line
P36 serves as a timer output (T
or the internal clock can be output. The counter/timers can
be cascaded by connecting the T0 output to the input of
T1.
Write
Write
Internal Data Bus
Internal Data Bus
Initial Value
Initial Value
Register
Register
Counter
Counter
Down
Down
8-Bit
8-bit
T0
T1
Read
Read
2
Z8 4K OTP Microcontroller
Current Value
Current Value
OUT
Register
Register
) through which T0, T1
T0
T1
Z86E30/E31/E40
TOUT
P36
IRQ5
IRQ4
39
1