STE10A Datasheet, PDF (26/82 Pages) STMicroelectronics – PCI 10/100 Ethernet controller with integrated PHY (3.3V)

Functional description
STE10/100A
Receive operation for PAUSE function
Upon reception of a valid MAC Control frame, the STE10/100A will start a timer for the
length of time specified by the MAC control parameters field. When the timer value reaches
zero, the STE10/100A exits the PAUSE state. However, a PAUSE frame will not affect the
transmission of a frame that has been submitted to the MAC (i.e., once a transmit out of the
MAC is begun, it can’t be interrupted). Conversely, the STE10/100A will not begin to transmit
a frame more than one slot-time after valid PAUSE frame is received a with a non-zero
PAUSE time. If the STE10/100A receives a PAUSE frame with a zero PAUSE time value, the
STE10/100A exits the PAUSE state immediately.
Figure 15. Pause operation receive state diagram
Opcode = PAUSE function
Wait for transmission completed
Transmission_in_progress = false *
DA = (01-80-C2-00-00-01 + Phys-address)
DA ≠ (01-80-C2-00-00-01 + Phys-address)
PAUSE function
n_slots_rx = data [17:32]
Start pause_timer (n_slots_rx * slot_time)
UCT
END PAUSE
PC00359
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