Texas Instruments TMS320C6454 - Manual (Page 187)

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PRODUCT PREVIEW
7.14 Ethernet MAC (EMAC)
Configuration Bus
DMA Memory
Transfer Controller
Peripheral Bus
EMAC Control Module
EMAC Module MDIO Module
MDIO Bus
EMAC/MDIO
Interrupt
Interrupt
Controller
Ethernet Bus
TMS320C6454
Fixed-Point Digital Signal Processor
SPRS311A – APRIL 2006 – REVISED DECEMBER 2006
The Ethernet Media Access Controller (EMAC) module provides an efficient interface between the C6454
DSP core processor and the networked community. The EMAC supports 10Base-T (10 Mbits/second
[Mbps]), and 100BaseTX (100 Mbps), in either half- or full-duplex mode, and 1000BaseT (1000 Mbps) in
full-duplex mode, with hardware flow control and quality-of-service (QOS) support.
The EMAC module conforms to the IEEE 802.3-2002 standard, describing the “Carrier Sense Multiple
Access with Collision Detection (CSMA/CD) Access Method and Physical Layer” specifications. The IEEE
802.3 standard has also been adopted by ISO/IEC and re-designated as ISO/IEC 8802-3:2000(E).
Deviation from this standard, the EMAC module does not use the Transmit Coding Error signal MTXER.
Instead of driving the error pin when an underflow condition occurs on a transmitted frame, the EMAC will
intentionally generate an incorrect checksum by inverting the frame CRC, so that the transmitted frame
will be detected as an error by the network.
The EMAC control module is the main interface between the device core processor, the MDIO module,
and the EMAC module. The relationship between these three components is shown in
Figure 7-58 . The
EMAC control module contains the necessary components to allow the EMAC to make efficient use of
device memory, plus it controls device interrupts. The EMAC control module incorporates 8K-bytes of
internal RAM to hold EMAC buffer descriptors. The relationship between these three components is
shown in
Figure 7-58 .
Figure 7-58. EMAC, MDIO, and EMAC Control Modules
For more detailed information on the EMAC/MDIO, see the TMS320C645x DSP EMAC/MDIO Module
Reference Guide (literature number
SPRU975 ).
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