LPC2458FET180,551 NXP Semiconductors, LPC2458FET180,551 Datasheet - Page 270

• Manufacturer Part Number: LPC2458FET180,551
• Description: IC ARM7 MCU FLASH 512K 180TFBGA
• Manufacturer: NXP Semiconductors
• Series: LPC2400r

Specifications of LPC2458FET180,551

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 72MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 136
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 98K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 180-TFBGA
• Processor Series: LPC24
• Core: ARM7TDMI-S
• Data Bus Width: 32 bit
• Data Ram Size: 98 KB
• Interface Type: CAN, Ethernet, I2C, I2S, IrDA, SPI, SSP, UART, USB
• Maximum Clock Frequency: 72 MHz
• Number Of Programmable I/os: 136
• Number Of Timers: 4
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2, SAB-TFBGA180
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• On-chip Dac: 10 bit, 1 Channel
• Package: 180TFBGA
• Device Core: ARM7TDMI-S
• Family Name: LPC2000
• Maximum Speed: 72 MHz
• For Use With: 622-1023 - BOARD SCKT ADAPTER FOR TFBGA180622-1005 - USB IN-CIRCUIT PROG ARM7 LPC2K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 568-4258; 935282454551; LPC2458FET180-S

NXP Semiconductors
UM10237_4
User manual
9.14 Power management
An imperfect filter is available, based on a hash mechanism. This filter applies a hash
function to the destination address and uses the hash to access a table that indicates if
the frame should be accepted. The advantage of this type of filter is that a small table can
cover any possible address. The disadvantage is that the filtering is imperfect, i.e.
sometimes frames are accepted that should have been discarded.
Enabling and disabling filtering
The filters as defined in the sections above can be bypassed by setting the PassRxFilter
bit in the Command register. When the PassRxFilter bit is set, all receive frames will be
passed to memory. In this case the device driver software has to implement all filtering
functionality in software. Setting the PassRxFilter bit does not affect the runt frame filtering
as defined in the next section.
Runt frames
A frame with less than 64 bytes (or 68 bytes for VLAN frames) is shorter than the
minimum Ethernet frame size and therefore considered erroneous; they might be collision
fragments. The receive datapath automatically filters and discards these runt frames
without writing them to memory and using a receive descriptor.
When a runt frame has a correct CRC there is a possibility that it is intended to be useful.
The device driver can receive the runt frames with correct CRC by setting the
PassRuntFrame bit of the Command register to 1.
The Ethernet block supports power management by means of clock switching. All clocks
in the Ethernet core can be switched off. If Wake-up on LAN is needed, the rx_clk should
not be switched off.
•
•
Hash function:
– The standard Ethernet cyclic redundancy check (CRC) function is calculated from
– The device driver can initialize the hash filter table by writing to the registers
Multicast and unicast
– The imperfect hash filter can be applied to multicast addresses, by setting the
– The same imperfect hash filter that is available for multicast addresses can also be
the 6 byte destination address in the Ethernet frame (this CRC is calculated
anyway as part of calculating the CRC of the whole frame), then bits [28:23] out of
the 32 bits CRC result are taken to form the hash. The 6 bit hash is used to access
the hash table: it is used as an index in the 64 bit HashFilter register that has been
programmed with accept values. If the selected accept value is 1, the frame is
accepted.
HashFilterL and HashfilterH. HashFilterL contains bits 0 through 31 of the table
and HashFilterH contains bit 32 through 63 of the table. So, hash value 0
corresponds to bit 0 of the HashfilterL register and hash value 63 corresponds to
bit 31 of the HashFilterH register.
AcceptMulticastHashEn bit in the RxFilter register to 1.
used for unicast addresses. This is useful to be able to respond to a multitude of
unicast addresses without enabling all unicast addresses. The hash filter can be
applied to unicast addresses by setting the AcceptUnicastHashEn bit in the
RxFilter register to 1.
Rev. 04 — 26 August 2009
Chapter 11: LPC24XX Ethernet
UM10237
© NXP B.V. 2009. All rights reserved.
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