Z86L04/L08
Z8 8-Bit Cost-Effective Microcontrollers
Zilog
Comparator Inputs. Two analog comparators are added
to input of Port 3, P31 and P32, for interface flexibility. The
comparators reference voltage P33 (REF) is common to
both comparators.
The dual comparator (common inverting terminal) features
a single power supply which discontinues power in STOP
mode. The common voltage range is 0-4V when the V
CC
is 5.0V; the power supply and common mode rejection ra-
tios are 90 dB and 60 dB, respectively.
1
Typical applications for the on-board comparators; Zero
crossing detection, A/D conversion, voltage scaling, and
threshold detection. In analog mode, P33 input functions
serve as a reference voltage to the comparators.
Interrupts are generated on either edge of Comparator 2's
output, or on the falling edge of Comparator 1's output.
The comparator output is used for interrupt generation,
Port 3 data inputs, or T through P31. Alternatively, the
IN
comparators can be disabled, freeing the reference input
(P33) for use as IRQ1 and/or P33 input.
FUNCTIONAL DESCRIPTION
The following special functions have been incorporated
into the Z86L04/L08 devices to enhance the standard Z8
core architecture to provide the user with increased design
flexibility.
RESET. This function is accomplished by means of a Pow-
er-On Reset or a Watch-Dog Timer Reset. Upon power-
up, the Power-On Reset circuit waits for T
ms, plus 18
POR
clock cycles, then starts program execution at address
000C (Hex) (Figure 10). The control registers' reset values
are shown in Table 3.
INT OSC
XTAL OSC
POR
(Cold Start)
18 CLK
Reset Filter
Delay Line
TPOR ms
Chip
Reset
P27
(Stop Mode)
Figure 10. Internal Reset Configuration
DS97LVO0901
P R E L I M I N A R Y
13
ZILOG [ ZILOG, INC. ]
