DSPIC33EP256MU810-I/PF Microchip Technology, DSPIC33EP256MU810-I/PF Datasheet - Page 424

• Manufacturer Part Number: DSPIC33EP256MU810-I/PF
• Description: 100 PINS, 256KB Flash, 28KB RAM, 60 MHz, USB, 2xCAN, 15 DMA 100 TQFP 14x14x1mm T
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33EPr

Specifications of DSPIC33EP256MU810-I/PF

• Processor Series: DSPIC33E
• Core: dsPIC
• 3rd Party Development Tools: 52713-733, 52714-737, 53276-922, EWDSPIC
• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 60 MIPs
• Connectivity: CAN, I²C, IrDA, LIN, QEI, SPI, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 83
• Program Memory Size: 256KB (85.5K x 24)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 12K x 16
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 32x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP
• Lead Free Status / Rohs Status: Details

dsPIC33EPXXXMU806/810/814 and PIC24EPXXXGU810/814
27.1
The CRC module can be programmed for CRC
polynomials of up to the 32nd order, using up to 32 bits.
Polynomial length, which reflects the highest exponent
in the equation, is selected by the PLEN<4:0> bits
(CRCCON2<4:0>).
The CRCXORL and CRCXORH registers control which
exponent terms are included in the equation. Setting a
particular bit includes that exponent term in the
equation; functionally, this includes an XOR operation
on the corresponding bit in the CRC engine. Clearing
the bit disables the XOR.
TABLE 27-1:
DS70616E-page 424
PLEN<4:0>
X<31:16>
X<15:0>
CRC Control
Bits
Overview
CRC SETUP EXAMPLES FOR 16 AND 32-BIT POLYNOMIAL
0000 0000 0000 000x
0001 0000 0010 000x
16-bit Polynomial
01111
Preliminary
Bit Values
For example, consider two CRC polynomials, one a 16-
bit equation and the other a 32-bit equation:
To program these polynomials into the CRC generator,
set the register bits as shown in
Note that the appropriate positions are set to ‘1’ to
indicate that they are used in the equation (for example,
X26 and X23). The 0 bit required by the equation is
always XORed; thus, X0 is a don’t care. For a poly-
nomial of length N, it is assumed that the Nth bit will
always be used, regardless of the bit setting. Therefore,
for a polynomial length of 32, there is no 32nd bit in the
CRCxOR register.
x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7
0000 0100 1100 0001
0001 1101 1011 011x
+ x5 + x4 + x2 + x + 1
x16 + x12 + x5 + 1
 2009-2011 Microchip Technology Inc.
32-bit Polynomial
and
11111
Table
27-1.