MCIMX281AVM4B Freescale Semiconductor, MCIMX281AVM4B Datasheet - Page 1629

• Manufacturer Part Number: MCIMX281AVM4B
• Description: IC MPU I.MX28 1.2 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX281AVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

26.3.8.2 Frame Payload Padding
The IEEE specification defines a minimum frame length of 64 bytes. If the frame sent to
the MAC from the user application has a size smaller than 60 bytes, the MAC automatically
adds padding bytes (0x00) so that frames transmitted to the Ethernet link do not violate the
Ethernet minimum frame length specification. Transmit padding is always performed and
cannot be disabled.
If the MAC is not allowed to append a CRC (ff_tx_crc_fwd=1) the user application is
responsible for providing frames with a minimum length of 64 octets.
26.3.8.3 MAC Address Insertion
On each frame received from the Core transmit FIFO interface, the source MAC address
is optionally replaced by the address programmed on the configuration registers PADDR1
and PADDR2 (Core Configuration register TX_ADDR_INS set to '1') or is transparently
forwarded to the Ethernet line (Core Configuration register TX_ADDR_INS set to '0').
26.3.8.4 CRC-32 generation
The CRC-32 field is optionally generated and appended at the end of a Frame if the Frame
is transmitted to the Core with the Frame status bit ff_tx_crc_fwd set to '0' when ff_tx_eop
is asserted.
The CRC polynomial, as specified in the 802.3 Standard, is as follows:
Freescale Semiconductor, Inc.
i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
Figure 26-13. Frame Transmit Overview
Send Destination Address
send local MAC address
(overwrite FIFO data)
Send Preamble
send padding
(if necessary)
send payload
send CRC
Chapter 26 Ethernet Controller (ENET)
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