z8f083a ZiLOG Semiconductor, z8f083a Datasheet - Page 115

• Manufacturer Part Number: z8f083a
• Description: High-performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Comparator
Operation
Comparator Control Register Definitions
PS026308-1207
Caution:
Comparator Control Register
The Z8 Encore! F083A Series devices feature a general purpose comparator that compares
two analog input signals. A GPIO (
negative input (
reference. The output is available as an interrupt source or is routed to an external pin
using the GPIO multiplex. The comparator includes the following features:
•
•
•
One of the comparator inputs is connected to an internal reference, which is a user
selectable reference and is user programmable with 200 mV resolution.
The comparator may be powered down to save supply current. For more details, see
Control Register 0
di
ld cmp0
nop
nop
clr irq0 ; clear any spurious interrupts pending
ei
The comparator control register (CMPCTL) configures the comparator inputs and sets the
value of the internal voltage reference.
As a result of the propagation delay of the comparator, it is not recommended to enable
the comparator without first disabling interrupts and waiting for the comparator output
to settle. This delay prevents spurious interrupts after comparator enabling. The
following example describes how to safely enable the comparator:
Positive input is connected to a GPIO pin.
Negative input is connected to either a GPIO pin or an programmable internal reference.
Output is either an interrupt source or an output to an external pin.
; wait for output to settle
CINN
on page 34.
) is taken from either an external GPIO pin or from an internal
CINP
) pin provides the positive comparator input. The
Z8 Encore!
Product Specification
®
F083A Series
Comparator
Power
103