MCF51EM256CLL Freescale Semiconductor, MCF51EM256CLL Datasheet - Page 453

• Manufacturer Part Number: MCF51EM256CLL
• Description: IC MCU 32BIT 256KB FLASH 100LQFP
• Manufacturer: Freescale Semiconductor
• Series: MCF51EMr

Specifications of MCF51EM256CLL

• Core Processor: Coldfire V1
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LCD, LVD, PWM, WDT
• Number Of I /o: 63
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 16x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Processor Series: MCF51EM
• Core: ColdFire V1
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: RS-232, LIN
• Maximum Clock Frequency: 50 MHz
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JLINK-CF-BDM26, EWCF
• Development Tools By Supplier: DEMOEM
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

20.4.2
The CRC module extends its original programming model to allow faster CRC calculations on CF1 cores.
Memory offsets 0x4, 0x5, 0x6 and 0x7 are mapped (aliased) onto the CRCL register, in a way that the
CF1Core can execute 32-bit store instructions to write data to the CRC module. The code should use a
single mov.l store instruction to send four bytes beginning at address 0x4, which will be decomposed by
the platform into four sequential/consecutive byte writes to offsets 0x4-0x7 (all aliased to the CRCL
position).
In addition, reads from 0x4-0x7 return the contents of the CRCL register. Reads from 0x2-0x3
(unused/reserved) return 0x00. Writes to 0x2-0x3 have no effect.
Due to internal CF1Core characteristics, this approach provides a greater data transfer rate than the original
programming model used on HCS08 (single byte writes to CRCL position).
message calculation on CF1Core.
Freescale Semiconductor
Programming model extension for CF1Core
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
1
A string of 256 upper case “A”
characters with no line breaks
A string of 256 upper case “A”
characters with no line breaks
A string of 256 upper case “A”
characters with no line breaks
One common variation of CRC-CCITT require the message to be
augmented with zeros and a SEED=0xFFFF. The CRC module will
give the same results of this alternative implementation when
SEED=0x1D0F and no message augmentation.
“123456789”
“123456789”
“123456789”
“A”
0x1d0f
0x1d0f
0x1d0f
0x0000
0x0000
0xffff
0xffff
1
1
1
0x29b1
0x9479
0x31c3
0xabe3
0xea0b
0xe938
0xe5cc
Figure 20-5
Cyclic Redundancy Check (CRC)
illustrates a
20-7