DP83816-MAAP National Semiconductor, DP83816-MAAP Datasheet - Page 82

• Manufacturer Part Number: DP83816-MAAP
• Description: BOARD EVALUATION DP83816
• Manufacturer: National Semiconductor

Specifications of DP83816-MAAP

• Main Purpose: Interface, Ethernet
• Utilized Ic / Part: DP83816
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -

5.0 Buffer Management
txDescRead
txFIFOblock
txDescWrite
txFragRead
txDescRefr
txAdvance
State
txIdle
txDescRefr
XferDone
XferDone
txAdvance
XferDone && !OWN
CR:TXE && !CTDD
XferDone && OWN
CR:TXE && CTDD
(descCnt == 0) &&
(descCnt == 0) &&
link == NULL
link != NULL
XferDone
XferDone
XferDone
FifoAvail
!MORE
MORE
Event
link = NULL
(Continued)
txDescWrite
CR:TXE && CTDD
Figure 5-5 Transmit State Diagram
Table 5-5 Transmit State Tables
descCnt == 0 && (cmdsts & MORE)
txDescRead
txDescRead
txFIFOblock
txDescWrite
txFIFOblock
txFragRead
Next State
txDescRefr
descCnt == 0 && !(cmdsts & MORE)
txAdvance
txAdvance
txAdvance
link != NULL
txIdle
txIdle
txIdle
82
Start a burst transfer at address TXDP and a length
derived from TXCFG.
Start a burst transfer to refresh the link field of the current
descriptor.
Set ISR:TXIDLE.
Start a burst transfer into the TxDataFIFO from fragPtr.
The length will be the minimum of txFifoAvail and
descCnt.
Decrement descCnt accordingly.
Start a burst transfer to write the status back to the
descriptor, clearing the OWN bit.
Write the value of TXDP to the txDataFIFO as a handle.
TXDP <- txDescCache.link. Clear CTDD. Start a burst
transfer at address TXDP with a length derived from
TXCFG.
Set CTDD. Set ISR:TXIDLE. Clear CR:TXE.
txFifoBlock
XferDone && !OWN
txDescRead
CR:TXE && !CTDD
Actions
XferDone && OWN
FifoAvail
XferDone
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txFragRead