STE100 datasheet(53/66 Pages) STMICROELECTRONICS

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STE10/100

2 Octets of PAUSE time specified in the MAC Control parameter field to indicate the length of time

for which the destination is requested to inhibit data frame transmission.

Receive Operation for PAUSE function

Upon reception of a valid MAC Control frame, the STE10/100 will start a timer for the length of time

specified by the MAC Control Parameters field. When the timer value reaches zero, the STE10/100

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 STE10/100 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 STE10/100 receives a PAUSE frame with a zero

PAUSE time value, the STE10/100 exits the PAUSE state immediately.

Figure 15. PAUSE operation receive state diagram

Wait for Transmission Completed

transmission_in_progress = false *

≠ (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

Opcode = PAUSE Function

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