Z87C33 Datasheet, PDF (23/72 Pages) Zilog, Inc. – CMOS Z8® MCU Consumer Controller Processor

Z87C33
CMOS Z8“ MCU Consumer Controller Processor
17
OSC
D1 SMR
÷2
÷4
D0 SMR
16
Internal
Clock
External Clock
Clock
Logic
÷4
6-Bit
Down
Counter
8-Bit
Down
Counter
PRE0
Initial Value
Register
T0
Initial Value
Register
T0
Current Value
Register
Write
Write
Read
Internal Data Bus
÷2
6-Bit
Down
Counter
8-Bit
Down
Counter
IRQ4
T_OUT
P36
IRQ5
Internal Clock
Gated Clock
Triggered Clock
T_IN P31
PRE1
Initial Value
Register
T1
Initial Value
Register
T1
Current Value
Register
Write
Write
Read
Internal Data Bus
Figure 10.Counter/Timer Block Diagram
Interrupts. The Z8 features six different interrupts from six different sources.
These interrupts are maskable and prioritize. The six sources are divided as fol-
lows: four sources are claimed by Port 3 lines P33–P30, and two are claimed by
counter/timers (Interrupt Types, Sources, and Vectors). The Interrupt Mask Regis-
ter globally or individually enables or disables the six interrupt requests.
PS015601-1003