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STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

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RM0008<br />

Ethernet (ETH): media access control (MAC) with DMA controller<br />

Ethernet DMA receive descriptor list address register (ETH_DMARDLAR)<br />

Address offset: 0x100C<br />

Reset value: 0x0000 0000<br />

The Receive descriptor list address register points to the start of the receive descriptor list.<br />

The descriptor lists reside in the STM32F107xx's physical memory space <strong>and</strong> must be<br />

word-aligned. The DMA internally converts it to bus-width aligned address by making the<br />

corresponding LS bits low. Writing to the ETH_DMARDLAR register is permitted only when<br />

reception is stopped. When stopped, the ETH_DMARDLAR register must be written to<br />

before the receive Start comm<strong>and</strong> is given.<br />

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0<br />

SRL<br />

rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw<br />

Bits 31:0 SRL: Start of receive list<br />

This field contains the base address of the first descriptor in the receive descriptor list. The<br />

LSB bits [1/2/3:0] for 32/64/128-bit bus width) are internally ignored <strong>and</strong> taken as all-zero by<br />

the DMA. Hence these LSB bits are read only.<br />

Ethernet DMA transmit descriptor list address register (ETH_DMATDLAR)<br />

Address offset: 0x1010<br />

Reset value: 0x0000 0000<br />

The Transmit descriptor list address register points to the start of the transmit descriptor list.<br />

The descriptor lists reside in the STM32F107xx's physical memory space <strong>and</strong> must be<br />

word-aligned. The DMA internally converts it to bus-width-aligned address by taking the<br />

corresponding LSB to low. Writing to the ETH_DMATDLAR register is permitted only when<br />

transmission has stopped. Once transmission has stopped, the ETH_DMATDLAR register<br />

can be written before the transmission Start comm<strong>and</strong> is given.<br />

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0<br />

STL<br />

rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw<br />

Bits 31:0 STL: Start of transmit list<br />

This field contains the base address of the first descriptor in the transmit descriptor list. The<br />

LSB bits [1/2/3:0] for 32/64/128-bit bus width) are internally ignored <strong>and</strong> taken as all-zero by<br />

the DMA. Hence these LSB bits are read-only.<br />

Ethernet DMA status register (ETH_DMASR)<br />

Address offset: 0x1014<br />

Reset value: 0x0000 0000<br />

The Status register contains all the status bits that the DMA reports to the application. The<br />

ETH_DMASR register is usually read by the software driver during an interrupt service<br />

routine or polling. Most of the fields in this register cause the host to be interrupted. The<br />

ETH_DMASR register bits are not cleared when read. Writing 1 to (unreserved) bits in<br />

Doc ID 13902 Rev 9 935/995

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