MK50H25N ST Microelectronics, Inc., MK50H25N Datasheet - Page 42

• Manufacturer Part Number: MK50H25N
• Description: High Speed Link Level Controller
• Manufacturer: ST Microelectronics, Inc.

MK50H25
4.4.8 Link Reset
The following procedure should be followed to reset an established link.
1. Issue a Reset Request primitive (UPRIM=8).
2. Wait for a Reset Confirmation primitive (PPRIM=9) from the MK50H25 (indicating reception of UA
3. If a Reset Confirmation primitive is received, a link has been reset.
4. If a Disconnect Indication primitive (PPRIM=14) is received, the MK5025 was unable to reset the link.
4.4.9 Receiving Link Reset
The following procedure should be followed when receiving a request for link reset:
1. A Reset Indication primitive (PPRIM=8) will be received from the MK50H25 indicating the remote sta-
2. If able to reset, issue a Reset Response primitive (UPRIM=9) to indicate willingness to reset the link.
3. If unable to reset, issue a Disconnect Request primitive (UPRIM=14) to disconnect the link.
4.4.10 Receiving FRMR Frame
The following procedure should be followed when receiving a FRMR frame:
1. An Error Indication primitive (PPRIM=4) will be received from the MK50H25 indicating an error condi-
2. If able to reset the link, issue a Reset Response primitive (UPRIM=9) and wait for either a Reset Indi-
3. If unable to reset, issue a Disconnect Request primitive (UPRIM=14) to disconnect the link. Link con-
4.4.11 Exchanging Identification
The following procedure should be followed to exchange identification with the remote station:
1. The XIDE bit in CSR2 must be set prior to any identification exchange.
2. Place appropriate identification information in the XID/TEST Transmit buffer.
3. Issue an XID Request primitive (UPRIM=10)
4. If an XID Confirmation primitive (PPRIM=11) is received, the identification exchange has been per-
4.4.12 Receiving XID/TEST Frames
The following procedure should be performed when receiving XID/TEST frames:
1. A XID Indication primitive (PPRIM=10) or TEST Indication Primitive (PPRIM=12) will be received from
2. To respond, place the appropriate information in the XID/TEST transmit buffer and issue a XID/TEST
3. To refuse, issue a Disconnect Request primitive (UPRIM=14).
NOTE: A XID or TEST Indication primitive will only be issued if the XIDE bit is set in CSR2. Otherwise all
XID/TEST frames will automatically be refused and not recognized.
4.4.13 Disabling the MK50H25
The following procedure should be followed to disable the MK50H25:
1. Issue the STOP primitive through CSR1. This will disable the MK50H25 from receiving or transmitting.
4.4.14 Re-enabling the MK50H25
The same procedure should be followed for re-enabling the MK50H25 as was used to initalize upon
power up. If the Initialization Block and the hardware configuration have not changed, then steps 1,2,3,
4 and 5 of the intialization sequence may be omitted.
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frame in response to SABM sent).
The reason will be in the PPARM field of CSR1. Link connection procedures now must be performed
to re-establish the link.
tion has requested a resetting of the link.
tion. PPARM=2 will indicate a FRMR has been received. The I-field of the FRMR has been placed in
the receive buffer pointed to by the next available Receive Descriptor.
cation or a Disconnect Indication as described previously for Link Reset.
nection procedures now must be performed to re-establish the link.
formed, and the remote response is located in the XID/TEST Receive buffer.
the MK50H25 to indicate the reception of a XID or TEST frame. The information field of the received
XID or TEST frame will be located in the XID/TEST receive buffer.
Response Primitive (UPRIM=11/13).
The TD pin will be held high while the MK50H25 is in the Stopped mode. The STOP bit in CSR0 will
be set and interrupts will be disabled. If reception or transmission of a frame is in progress, then re-
ceived data may be lost, and the transmitted frame will be aborted.