OM13000 NXP Semiconductors, OM13000 Datasheet - Page 6

• Manufacturer Part Number: OM13000
• Description: BOARD LPCXPRESSO LPC1768
• Manufacturer: NXP Semiconductors
• Type: MCUr
• Series: LPCXpressor

Specifications of OM13000

• Contents: Board
• Svhc: No SVHC (18-Jun-2010)
• Mcu Supported Families: LPC1768
• Silicon Family Name: LPC17xx
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Ic Product Type: Debugger
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: LPC1768
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 568-5101

NXP Semiconductors
ES_LPC176X
Errata sheet
3.3 Ethernet.1: Ethernet TxConsumeIndex register does not update
correctly after the first frame is sent (LPC1769/68/67/66/64 only)
Introduction:
The transmit consume index register defines the descriptor that is going to be transmitted
next by the hardware transmit process. After a frame has been transmitted hardware
increments the index, wrapping the value to 0 once the value of TxDescriptorNumber has
been reached. If the TxConsumeIndex equals TxProduceIndex the descriptor array is
empty and the transmit channel will stop transmitting until software produces new
descriptors.
Problem:
The TxConsumeIndex register is not updated correctly (from 0 to 1) after the first frame is
sent. After the next frame sent, the TxConsumeIndex register is updated by two (from 0 to
2). This only happens the very first time, so subsequent updates are correct (even those
from 0 to 1, after wrapping the value to 0 once the value of TxDescriptorNumber has been
reached)
Work-around:
Software can correct this situation in many ways; for example, sending a dummy frame
after initialization.
All information provided in this document is subject to legal disclaimers.
Rev. 8 — 22 March 2011
Errata sheet LPC1769/68/67/66/65/64/63
ES_LPC176x
© NXP B.V. 2011. All rights reserved.
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