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For example, for
•For the
•Any single latency event in request servicing can be no longer than (0.512 * TXCELLTHRESH) μs.
Bits
2.15 Reset Considerations
2.15.1Software Reset Considerations
For information on the chip level reset capabilities of various peripherals, see the TMS320TCI6486 Communications Infrastructure Digital Signal Processor data manual (SPRS300) or the TMS320C6472
Within the peripheral itself, the EMAC component of the Ethernet MAC peripheral can be placed in a reset state by writing to the SOFTRESET register located in EMAC memory map. Writing a one to bit 0 of this register causes the EMAC logic to be reset, and the register values to be set to their default values. Software reset occurs when the receive and transmit DMA controllers are in an idle state to avoid locking up the configuration bus; it is the responsibility of the software to verify that there are no pending frames to be transferred. After writing a one to this bit, it may be polled to determine if the reset has occurred. A value of one indicates that the reset has not yet occurred. A value of zero indicates that a reset has occurred.
After a software reset operation, all the EMAC registers need to be
Unlike the EMAC module, the MDIO, EMIC modules, and CPPI buffer managers cannot be placed in reset from a register inside their memory map.
2.15.2Hardware Reset Considerations
When a hardware reset occurs, the EMAC peripheral will have its register values reset, and all the
A hardware reset is the only means of recovering from the error interrupts (HOSTPEND), which are triggered by errors in packet buffer descriptors. Before doing a hardware reset, you should inspect the error codes in the MACSTATUS register. This register provides information about the software error type that needs correction. For more information on error interrupts, see Section 2.17.1.4.
2.15.3RGMII Transmission
On device reset, packet transmissions on the RGMII interface are precluded for 4096 transmit clock cycles after the RGMII link signal goes high. Transmission can be started only after 4096 cycles of transmit clock after the link signal goes high. Any packet transmission attempt within 4096 clock cycles of transmit clock will not cause an actual packet transmission over the RGMII interface. This restriction on packet transmissions calls for a delay in the packet transmission after device reset. An approximate delay of 2 ms after reset should be enough to start packet transmissions.
2.15.4S3MII Transmission
On device reset, packet transmissions on the S3MII interface are precluded for 4096 transmit clock cycles after the S3MII link signal goes high. Transmission can be started only after 4096 cycles of transmit clock after the link signal goes high. Any packet transmission attempt within 4096 clock cycles of transmit clock will not cause an actual packet transmission over the S3MII interface. This restriction on packet transmissions calls for a delay in the packet transmission after device reset. An approximate delay of 2 ms after reset should be enough to start packet transmissions.
64 | C6472/TCI6486 EMAC/MDIO | SPRUEF8F |
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