z86e63 ZiLOG Semiconductor, z86e63 Datasheet - Page 27

• Manufacturer Part Number: z86e63
• Description: Cmos Z8 16k/32k Eprom Microcontroller
• Manufacturer: ZiLOG Semiconductor

PS014401-1001
Interrupts
T
Clock
Logic
IN
OSC
(single pass mode) or to automatically reload the initial value and continue count-
ing (modulo-n continuous mode).
The counter, but not the prescalers, are read at any time without disturbing their
value or count mode. The clock source for T1 is user-definable and is either the
internal microprocessor clock divided-by-four, or an external 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-retriggerable, or as
a gate input for the internal clock. Port 3 line P36 also serves as a timer output
(TOUT) through which T0, T1, or the internal clock can be output. The counter/
timers are cascaded by connecting the TO output to the input of T1.
+2
Figure 15. Counter/Timers Block Diagram
The Z86E61/E63 has six different interrupts from eight different sources. The
interrupts are maskable and prioritized. The eight sources are divided as follows:
four sources are claimed by Port 3 lines P33-P30, one in Serial Out, one in Serial
In, and two in the counter/timers (Figure 16). The Interrupt Mask Register globally
P31
External Clock
Internal Clock
Gated Clock
Triggered Clock
Internal
Clock
+4
+4
Write
Write
Initial Value
Initial Value
Register
Register
Counter
Counter
PRE1
Down
PRE0
Down
6-Bit
6-Bit
Write
CMOS Z8 16K/32K EPROM Microcontroller
Write
Internal Data Bus
Internal Data Bus
Initial Value
Initial Value
Register
Counter
Register
Counter
Down
Down
8-Bit
8-Bit
T1
T0
Read
Read
+2
Current Value
Current Value
Register
Register
T1
T0
Clock
IRQ5
IRQ4
Serial I/O
T
P36
OUT
Z86E61/E63
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