DSPIC33FJ12MC202T-I/SO Microchip Technology, DSPIC33FJ12MC202T-I/SO Datasheet - Page 8

• Manufacturer Part Number: DSPIC33FJ12MC202T-I/SO
• Description: 12KB, Flash, 1024bytes-RAM, 40MIPS, 21I/O, 16-bit Family,nanoWatt,MotorControl 2
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33Fr

Specifications of DSPIC33FJ12MC202T-I/SO

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 40 MIPs
• Connectivity: I²C, IrDA, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, Motor Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 21
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 6x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164339 - MODULE SKT FOR PM3 28SOICDM240001 - BOARD DEMO PIC24/DSPIC33/PIC32
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: DSPIC33FJ12MC202T-I/SOTR

25. Module: QEI
EXAMPLE 1:
DS80461E-page 8
unsigned int POSCNT_b15 = 0;
unsigned int Motor_Position = 0;
int main(void)
{
}
void __attribute__((__interrupt__)) _QEIInterrupt(void)
{
}
The Quadrature Encoder Interface (QEI) module
does not generate an interrupt when MAXCNT is
set to 0xFFFF and the following events occur:
1. POSCNT underflows from 0x0000 to 0xFFFF.
2. POSCNT stops.
3. POSCNT overflows from 0xFFFF to 0x0000.
This sequence of events occurs when the motor is
running in one direction, which causes POSCNT to
underflow to 0xFFFF. Then, if the motor stops and
starts running in the opposite direction an overflow
from 0xFFFF to 0x0000 will be generated. The QEI
module does not generate an interrupt when this
condition occurs.
Work around
To prevent this condition from occurring, set
MAXCNT to 0x7FFF, which will cause an interrupt
to be generated by the QEI module.
In addition, a global variable could be used to
monitor bit 15, so that when an overflow or
underflow condition is present on POSCNT, the
variable will toggle bit 15.
code required for this global variable.
Affected Silicon Revisions
A2
X
A3
X
// ... User's code
MAXCNT = 0x7FFF;
Motor_Position = POSCNT_b15 + POSCNT;
// ... User's code
IFSxbits.QEIIF = 0;
POSCNT_b15 ^= 0x8000; // Overflow or Underflow
A4
X
A5
X
Example 1
// Instead of 0xFFFF
// Clear QEI interrupt flag
// x=2 for dsPIC30F
// x=3 for dsPIC33F
shows the
26. Module: UART
The UART module will not generate consecutive
break characters. Trying to perform a back-to-back
Break character transmission will cause the UART
module to transmit the dummy character used to
generate the first Break character instead of
transmitting the second Break character. Break
characters are generated correctly if they are
followed by non-Break character transmission.
Work around
None.
Affected Silicon Revisions
A2
X
A3
X
A4
X
© 2010 Microchip Technology Inc.
A5
X