PIC18F2331-I/SP Microchip Technology, PIC18F2331-I/SP Datasheet - Page 164

• Manufacturer Part Number: PIC18F2331-I/SP
• Description: IC PIC MCU FLASH 4KX16 28DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2331-I/SP

• Program Memory Type: FLASH
• Program Memory Size: 8KB (4K x 16)
• Package / Case: 28-DIP (0.300", 7.62mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, Power Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 24
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: EUSART/I2C/SPI/SSP
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 24
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE4000, ICE2000, DM183021, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 5-ch x 10-bit
• Package: 28SPDIP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: I3-DB18F4431 - BOARD DAUGHTER ICEPIC3AC164035 - MODULE SKT FOR 18F2X31 28SOICDVA18XP280 - DEVICE ADAPTER 18F2220 PDIP 28LD
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2331/2431/4331/4431
17.2.3.3
The position counter will continue to increment or dec-
rement until one of the following events takes place.
The type of event and the direction of rotation when it
happens determines if a register Reset or update
occurs.
1.
2.
The value of the position counter is not affected during
QEI mode changes, nor when the QEI is disabled
altogether.
DS39616D-page 164
An index pulse is detected on the INDX input
(QEIM<2:0> = 001).
If the encoder is traveling in the forward direc-
tion, POSCNT is reset (00h) on the next clock
edge after the index marker, INDX, has been
detected. The position counter resets on the
QEA or QEB edge once the INDX rising edge
has been detected.
If the encoder is traveling in the reverse direc-
tion, the value in the MAXCNT register is loaded
into POSCNT on the next quadrature pulse
edge (QEA or QEB) after the falling edge on
INDX has been detected.
A POSTCNT/MAXCNT period match occurs
(QEIM<2:0> = 010).
If the encoder is traveling in the forward direc-
tion, POSCNT is reset (00h) on the next clock
edge when POSCNT = MAXCNT. An interrupt
event is triggered on the next T
(see
If the encoder is traveling in the reverse
direction and the value of POSCNT reaches
00h, POSCNT is loaded with the contents of the
MAXCNT register on the next clock edge. An
interrupt event is triggered on the next T
the load operation (see
Figure
Reset and Update Events
17-10)
Figure
CY
17-10).
after the Reset
CY
after
17.2.4
The position counter interrupt occurs and the interrupt
flag (IC2QEIF) is set, based on the following events:
• A POSCNT/MAXCNT period match event
• A POSCNT rollover (FFFFh to 0000h) in Period
• An index pulse detected on INDX
The interrupt timing diagrams for IC2QEIF are shown in
Figure 17-10
When the direction has changed, the direction change
interrupt flag (IC3DRIF) is set on the following T
clock (see
If the position counter rolls over in Index mode, the
QERR bit will be set.
17.2.5
The quadrature input signals, QEA and QEB, may vary
in quadrature frequency. The minimum quadrature
input period, T
The position count rate, F
the rotor’s RPM, line count D and QEI Update mode (x2
versus x4); that is,
EQUATION 17-1:
The maximum position count rate (i.e., x4 QEI
Update mode, D = 1024) with F
to 2.5 MHz, which corresponds to F
Figure 17-9
timing when sampled by the noise filter.
(QEIM<2:0> = 010 or 110)
mode only (QEIM<2:0> = 010 or 110)
Note:
Figure
QEI INTERRUPTS
QEI SAMPLE TIMING
The number of incremental lines in the
position encoder is typically set at D = 1024
and the QEI Update mode = x4.
shows QEA and QEB quadrature input
and
QEI
, is 16 T
Figure
17-10).
F
POS
= 4D • RPM
 2010 Microchip Technology Inc.
17-11.
POS
CY
.
, is directly proportional to
60
CY
= 10 MIPS is equal
QEI
of 625 kHz.
CY