AM79C901AJCT AMD [Advanced Micro Devices], AM79C901AJCT Datasheet - Page 24

• Manufacturer Part Number: AM79C901AJCT
• Description: HomePHY Single-Chip 1/10 Mbps Home Networking PHY
• Manufacturer: AMD [Advanced Micro Devices]

24
Note: TXCLK continues to toggle until the SFD is observed, as shown in the first section of the above diagram.
At this point, TXCLK is disabled (low) until the AID header has been transmitted on the wire (or until a CLS has
been detected). At this time RXCLK starts toggling, thereby, shifting 32 bits of preamble and SFD back to the
MAC. Sometime later, the TXCLK restarts as symbols get sent onto the wire in an analogous manner as
RXCLK during packet reception.
Note: Once TXEN is asserted, the PHY stops RXCLK, asserts RXCRS, and toggles TXCLK.
RXCRS
RXCRS
RXDAT
RXCLK
RXDAT
TXDAT
RXCLK
TXCLK
TXDAT
TXCLK
TXEN
CLS
TXEN
CLS
Figure 4.
Figure 5. TXPKT - RXCLK Active
P R E L I M I N A R Y
TXPKT - TXEN Asserted
Am79C901A
22304B-7
22304B-6