M3087BFLBGP#U5 Renesas Electronics America, M3087BFLBGP#U5 Datasheet - Page 340

• Manufacturer Part Number: M3087BFLBGP#U5
• Description: IC M32C/87 MCU FLASH 144LQFP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M32C/80r

Specifications of M3087BFLBGP#U5

• Core Processor: M32C/80
• Core Size: 16/32-Bit
• Speed: 32MHz
• Connectivity: EBI/EMI, I²C, IEBus, IrDA, SIO, UART/USART
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 121
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 34x10b, D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 144-LQFP
• For Use With: R0K330879S001BE - KIT DEV RSK M32C/87R0K330879S000BE - KIT DEV RSK M32C/87
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

M32C/87 Group (M32C/87, M32C/87A, M32C/87B)
REJ09B0180-0151 Rev.1.51 Jul 31, 2008
Page 316 of 587
20. CRC Calculation
The CRC (Cyclic Redundancy Check) calculation detects an error in data blocks. A generator polynomial of CRC -
CCITT (X
The CRC code is a 16-bit code generated for a given length of the data block in bytes. The CRC code is stored in the
CRCD register every time one-byte data is transferred to the CRCIN register after a default value is written to the
CRCD register. CRC code generation for one-byte data is completed in two bus clock cycles.
Figure 20.1 shows a block diagram of the CRC circuit. Figure 20.2 shows CRC-associated registers. Figure 20.3
shows an example of the CRC calculation.
Figure 20.1
Figure 20.2
CRC Data Register
CRC Input Register
b15
b7
16
b8 b7
+ X
12
CRC Calculation Block Diagram
CRCD Register, CRCIN Register
+ X
5
b0
b0
+ 1) generates CRC code.
After an initial value is written to the CRCD register, the CRC code
can be read from the CRCD register by writing data to the CRCIN
register. Bit position of the initial value is inverted. The inverted
value is read as the CRC code.
Data input.
Inverse bit position of data
Symbol
CRCD
Symbol
CRCIN
CRCIN register
High-order bits of data bus
Low-order bits of data bus
CRC code generation circuit
Function
Function
8 low-order bits
X
CRCD register
16
+ X
12
Address
037Dh - 037Ch
Adddress
037Eh
+ X
5
+ 1
8 high-order bits
0000h to FFFFh
Setting Range
Setting Range
00h to FFh
After Reset
Undefined
After Reset
Undefined
20. CRC Calculation
RW
RW
RW
RW