PIC18F2331 MICROCHIP [Microchip Technology], PIC18F2331 Datasheet - Page 178

• Manufacturer Part Number: PIC18F2331
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2331/2431/4331/4431
16.2.6.1
The event pulses are reduced by a fixed ratio by the
velocity pulse divider. The divider is useful for
high-speed measurements where the velocity events
happen frequently. By producing a single output pulse
for a given number of input event pulses, the counter
can track larger pulse counts (i.e., distance travelled)
for a given time interval. Time is measured by utilizing
the TMR5 time base.
FIGURE 16-12:
DS39616B-page 176
CAP3/QEB
CAP2/QEA
CAP1/INDX
Velocity Event Timing
VELOCITY MEASUREMENT BLOCK DIAGRAM
QEB
QEA
INDX
QEI
Control
Logic
Velocity Event
Direction
Clock
Preliminary
Postscaler
Reset
Logic
Position
Counter
TMR5 Reset
Each velocity pulse serves as a capture pulse. With the
TMR5 in Synchronous Timer mode, the value of TMR5
is captured on every output pulse of the postscaler. The
counter is subsequently reset to ‘0’. TMR5 is reset
upon a capture event.
Figure 16-13 shows the velocity measurement timing
diagram.
Velocity Capture
(VELR Register)
TMR5
 2003 Microchip Technology Inc.
IC1
16
Clock
Velocity Mode
T
CY