PIC18F2431-I/SP Microchip Technology Inc., PIC18F2431-I/SP Datasheet - Page 168

• Manufacturer Part Number: PIC18F2431-I/SP
• Description: Microcontroller; 16 KB Flash; 768 RAM; 256 EEPROM; 24 I/O; 28-Pin-SPDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F2431-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 24
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 16K Bytes
• Ram Size: 768 Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2331/2431/4331/4431
16.1.3.1
Pulse width measurement accuracy can be only
ensured when the pulse width high and low present on
CAPx input exceeds one T
limitations depend on the mode selected:
• When CAPxM3:CAPxM0 = 0110 (rising-to-falling
• When CAPxM3:CAPxM0 = 0111 (falling-to-rising
FIGURE 16-6:
DS39616B-page 166
edge delay), the CAPx input high pulse width
(TccH) must exceed T
edge delay), the CAPx input low pulse width
(TccL) must exceed T
Note 1: The Period Measurement mode will
Note 1: TMR5 can be selected as the time base for input capture. Time base can be optionally reset when the capture reset
CAP1
CAP2
CAP3
Time Base
CAP1BUF
CAP2BUF
CAP3BUF
Time Base Reset
2: The Pulse Width Measurement mode will
2: Detailed CAPxBUF event timing (all modes reflect same capture and Reset timing) is shown in Figure 16-4.There are
produce valid results upon sampling of
the second rising edge of the input
capture. CAPxBUF values latched during
the first active edge after initialization are
invalid.
latch the value of the timer upon sampling
of the first input signal edge by the input
capture.
enabled bit is set (CAPXREN = 1).
six commutation BLDC hall-effect sensor states shown. The other two remaining states (i.e., 000h and 111h) are
invalid in the normal operation. They are still to be decoded by the CPU firmware in BLDC motor application.
Pulse Width Measurement Timing
(2)
(2)
(2)
(1)
0FFFh
0000h
INPUT CAPTURE ON STATE CHANGE (HALL-EFFECT SENSOR MODE)
(1)
CY
CY
+ 10 ns.
+ 10 ns.
CY
clock cycle. The
1
0
1
1
0
0
1
0
1
Preliminary
0
1
0
0
1
1
16.1.4
When CAPxM3:CAPxM0 = 1000, the value is captured
on every signal change on the CAPx input. If all three
capture channels are configured in this mode, the
three-input-capture can be used as the Hall-effect
sensor state transition detector. The value of Timer5
can be captured, Timer5 reset and the interrupt
generated. Any change on CAP1, CAP2 or CAP3 is
detected and the associated time base count is
captured.
For position and velocity measurement in this mode,
the timer can be optionally reset (see Section 16.1.6
“Timer5 Reset” for Reset options).
0
1
0
INPUT CAPTURE ON STATE
CHANGE
 2003 Microchip Technology Inc.