DSPIC30F4011-20E/PT Microchip Technology, DSPIC30F4011-20E/PT Datasheet - Page 92

• Manufacturer Part Number: DSPIC30F4011-20E/PT
• Description: IC DSPIC MCU/DSP 48K 44TQFP
• Manufacturer: Microchip Technology
• Series: dsPIC™ 30Fr

Specifications of DSPIC30F4011-20E/PT

• Program Memory Type: FLASH
• Program Memory Size: 48KB (16K x 24)
• Package / Case: 44-TQFP, 44-VQFP
• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 20 MIPS
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, Motor Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 30
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 5.5 V
• Data Converters: A/D 9x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Data Bus Width: 16 bit
• Processor Series: DSPIC30F
• Core: dsPIC
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 30
• Data Ram Size: 2 KB
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52713-733, 52714-737, 53276-922, EWDSPIC
• Data Rom Size: 1024 B
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE4000, DM240002, DM300018, DM330011
• Minimum Operating Temperature: - 40 C
• Package: 44TQFP
• Device Core: dsPIC
• Family Name: dsPIC30
• Maximum Speed: 20 MHz
• Interface Type: CAN/I2C/SPI/UART
• On-chip Adc: 9-chx10-bit
• Number Of Timers: 5
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC30F006 - MODULE SKT FOR DSPIC30F 44TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: DSPIC30F401120EPT

dsPIC30F4011/4012
14.1
A typical, incremental (a.k.a. optical) encoder has three
outputs: Phase A, Phase B and an index pulse. These
signals are useful and often required in position and
speed control of ACIM and SR motors.
The two channels, Phase A (QEA) and Phase B (QEB),
have a unique relationship. If Phase A leads Phase B,
then the direction (of the motor) is deemed positive or
forward. If Phase A lags Phase B, then the direction (of
the motor) is deemed negative or reverse.
A third channel, termed index pulse, occurs once per
revolution and is used as a reference to establish an
absolute position. The index pulse coincides with
Phase A and Phase B, both low.
14.2
The 16-bit Up/Down Counter counts up or down on
every count pulse, which is generated by the difference
of the Phase A and Phase B input signals. The counter
acts as an integrator, whose count value is proportional
to position. The direction of the count is determined by
the UPDN signal which is generated by the Quadrature
Encoder Interface Logic.
14.2.1
Position counter error checking in the QEI is provided
for and indicated by the CNTERR bit (QEICON<15>).
The error checking only applies when the position
counter is configured for Reset on the Index Pulse
modes (QEIM<2:0> = 110 or 100). In these modes, the
contents of the POSCNT register are compared with
the values (0xFFFF or MAXCNT + 1, depending on
direction). If these values are detected, an error condi-
tion is generated by setting the CNTERR bit and a QEI
count error interrupt is generated. The QEI count error
interrupt can be disabled by setting the CEID bit
(DFLTCON<8>). The position counter continues to
count encoder edges after an error has been detected.
The POSCNT register continues to count up/down until
a natural rollover/underflow. No interrupt is generated
for the natural rollover/underflow event. The CNTERR
bit is a read/write bit and reset in software by the user.
DS70135G-page 92
Quadrature Encoder Interface
Logic
16-bit Up/Down Position Counter
Mode
POSITION COUNTER ERROR
CHECKING
14.2.2
The Position Counter Reset Enable bit, POSRES (QEI-
CON<2>) controls whether the position counter is reset
when the index pulse is detected. This bit is only
applicable when QEIM<2:0> = 100 or 110.
If the POSRES bit is set to ‘1’, then the position counter
is reset when the index pulse is detected. If the
POSRES bit is set to ‘0’, then the position counter is not
reset when the index pulse is detected. The position
counter will continue counting up or down and will be
reset on the rollover or underflow condition.
When selecting the INDX signal to reset the position
counter (POSCNT), the user has to specify the states
on the QEA and QEB input pins. These states have to
be matched in order for a Reset to occur. These states
are selected by the IMV<1:0> bits (DFLTCON<10:9>).
The Index Match Value bits (IMV<1:0>) allow the user
to specify the state of the QEA and QEB input pins,
during an index pulse, when the POSCNT register is to
be reset.
In 4x Quadrature Count mode:
IMV1 = Required state of Phase B input signal for
IMV0 = Required state of Phase A input signal for
In 2x Quadrature Count mode:
IMV1 = Selects phase input signal for index state
IMV0 = Required state of the selected phase input
The interrupt is still generated on the detection of the
index pulse and not on the position counter overflow/
underflow.
14.2.3
As mentioned in the previous section, the QEI logic
generates an UPDN signal, based upon the relation-
ship between Phase A and Phase B. In addition to the
output pin, the state of this internal UPDN signal is
supplied to an SFR bit, UPDN (QEICON<11>), as a
read-only bit.
Note:
match on index pulse
match on index pulse
match (0 = Phase A, 1 = Phase B)
signal for match on index pulse
POSITION COUNTER RESET
COUNT DIRECTION STATUS
QEI pins are multiplexed with analog
inputs. The user must insure that all QEI
associated pins are set as digital inputs in
the ADPCFG register.
© 2010 Microchip Technology Inc.