MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 883

• Manufacturer Part Number: MCBSTM32EXL
• Description: BOARD EVALUATION FOR STM32F103ZE
• Manufacturer: Keil

Specifications of MCBSTM32EXL

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

RM0008
Figure 311. TxDMA operation in Default mode
TxDMA operation: OSF mode
While in the Run state, the transmit process can simultaneously acquire two frames without
closing the Status descriptor of the first (if the OSF bit is set in ETH_DMAOMR register[2]).
As the transmit process finishes transferring the first frame, it immediately polls the transmit
descriptor list for the second frame. If the second frame is valid, the transmit process
transfers this frame before writing the first frame’s status information. In OSF mode, the
Run-state transmit DMA operates according to the following sequence:
TxDMA suspended
Close intermediate
Poll demand
descriptor
Ethernet (ETH): media access control (MAC) with DMA controller
Doc ID 13902 Rev 9
No
No
No
Transfer data from
Wait for Tx status
Write status word
(Re-)fetch next
Start TxDMA
Time stamp
Frame xfer
complete?
descriptor
to TDES0
present?
buffer(s)
bit set?
(AHB)
(AHB)
(AHB)
error?
error?
error?
Own
Yes
No
No
Yes
No
Yes
Start
No
Write time stamp to
TDES2 and TDES3
Stop TxDMA
Yes
Yes
Yes
(AHB)
error?
Yes
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