MCBSTM32EXL Keil, MCBSTM32EXL Datasheet - Page 934

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

Specifications of MCBSTM32EXL

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

Ethernet (ETH): media access control (MAC) with DMA controller
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31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
Bits 31:0 TPD: Transmit poll demand
Bits 31:0 RPD: Receive poll demand
Ethernet DMA transmit poll demand register (ETH_DMATPDR)
Address offset: 0x1004
Reset value: 0x0000 0000
This register is used by the application to instruct the DMA to poll the transmit descriptor list.
The transmit poll demand register enables the Transmit DMA to check whether or not the
current descriptor is owned by DMA. The Transmit Poll Demand command is given to wake
up the TxDMA if it is in Suspend mode. The TxDMA can go into Suspend mode due to an
underflow error in a transmitted frame or due to the unavailability of descriptors owned by
transmit DMA. You can issue this command anytime and the TxDMA resets it once it starts
re-fetching the current descriptor from host memory.
EHERNET DMA receive poll demand register (ETH_DMARPDR)
Address offset: 0x1008
Reset value: 0x0000 0000
This register is used by the application to instruct the DMA to poll the receive descriptor list.
The Receive poll demand register enables the receive DMA to check for new descriptors.
This command is given to wake up the RxDMA from Suspend state. The RxDMA can go into
Suspend state only due to the unavailability of descriptors owned by it.
When these bits are written with any value, the DMA reads the current descriptor pointed to by
the ETH_DMACHTDR register. If that descriptor is not available (owned by Host), transmission
returns to the Suspend state and ETH_DMASR register bit 2 is asserted. If the descriptor is
available, transmission resumes.
When these bits are written with any value, the DMA reads the current descriptor pointed to by
the ETH_DMACHRDR register. If that descriptor is not available (owned by Host), reception
returns to the Suspended state and ETH_DMASR register bit 7 is not asserted. If the
descriptor is available, the Receive DMA returns to active state.
Doc ID 13902 Rev 9
rw_wt
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RPD
TPD
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RM0008
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