MA180025 Microchip Technology, MA180025 Datasheet - Page 309

• Manufacturer Part Number: MA180025
• Description: MODULE PLUG-IN PIC18F87J90 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180025

• Accessory Type: Plug-In Module (PIM) - PIC18F87J90
• Product: Microcontroller Modules
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PICDEM LCD 2 Demonstration Board (DM163030)
• For Use With: DM163030 - KIT DEV PICDEM LCD2
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

24.0
The Charge Time Measurement Unit (CTMU) is a
flexible analog module that provides accurate differen-
tial time measurement between pulse sources, as well
as asynchronous pulse generation. By working with
other on-chip analog modules, the CTMU can be used
to precisely measure time, measure capacitance,
measure relative changes in capacitance or generate
output pulses with a specific time delay. The CTMU is
ideal for interfacing with capacitive-based sensors.
The module includes the following key features:
• Up to 13 channels available for capacitive or time
• On-chip precision current source
• Four-edge input trigger sources
• Polarity control for each edge source
FIGURE 24-1:
 2010 Microchip Technology Inc.
measurement input
CTEDG1
CTEDG2
CHARGE TIME
MEASUREMENT UNIT (CTMU)
CCP2
CCP1
CTMU BLOCK DIAGRAM
EDGEN
EDGSEQEN
EDG1SELx
EDG1POL
EDG2SELx
EDG2POL
Control
Edge
Logic
EDG1STAT
EDG2STAT
A/D Converter
Current Source
CTMUICON
CTMUCON
Current
Control
Comparator 2
PIC18F87J90 FAMILY
Input
ITRIM<5:0>
IRNG<1:0>
• Control of edge sequence
• Control of response to edges
• Time measurement resolution of 1 nanosecond
• High-precision time measurement
• Time delay of external or internal signal
• Accurate current source suitable for capacitive
The CTMU works in conjunction with the A/D Converter
to provide up to 13 channels for time or charge
measurement, depending on the specific device and the
number of A/D channels available. When configured for
time delay, the CTMU is connected to one of the analog
comparators. The level-sensitive input edge sources
can be selected from four sources: two external inputs or
the CCP1/CCP2 Special Event Triggers.
Figure 24-1 provides a block diagram of the CTMU.
asynchronous to the system clock
measurement
Comparator 2 Output
Generator
Control
CTMU
Logic
Pulse
TGEN
IDISSEN
CTTRIG
DS39933D-page 309
A/D Trigger
CTPLS