
116
Functional Operation
Chapter 3
AMD-8111 HyperTransport I/O Hub Data Sheet
24674
Rev. 3.00
April 2003
AMD Preliminary Information
To control the auto-negotiation process, the Network Port Manager generates MII Management
Frames to execute the procedure described below.
The Network Port Manager is held in the IDLE state while H_RESET is asserted and while the
EN_PMGR bit is cleared. When none of these conditions are true, the Network Port Manager
proceeds through the following steps:
1. If XPHYRST is set, write to the PHY's Control Register (R0) to set the Soft Reset bit and cause
the PHY to reset. The Network Port Manager then periodically reads the PHY's Control Register
(R0) until the reset is complete.
2. If XPHYRST is not set or after the PHY reset is complete, the PHY's Status Register (R1) is read.
3. If the PHY's Auto-Negotiation Ability bit (R1, bit 3) is 0 or if the XPHYANE bit in the Control2
Register is 0 and if this is the first pass through this procedure since EN_PMGR was set to 1, write
to the PHY's Control Register (R0) to disable auto-negotiation and set the speed and duplex mode
to the values specified by the XPHYSP and XPHYFD bits in the Control2 Register ANDed with
the appropriate bits from the PHY's Technology Ability Field. Then proceed to step 8.
4. If this is the first pass through this procedure since EN_PMGR was set to 1, write to the Auto-
Negotiation Advertisement Register (R4). Bits A0 to A4 of the Technology Ability field of R4 are
taken from bits 15 to 11 in R1. (The Technology Ability field of R4 consists of bits 5 through 12,
where bit 5 of R4 corresponds to Technology Ability bit A0.) Bit A5 of the Technology Ability
field indicates the MAC's ability to respond to MAC Control Pause frames. This bit is set equal to
the value of the Negotiate Pause Ability (NPA) bit in the Flow Control Register. Bit A6 indicates
Asymmetric PAUSE operation for full-duplex links. This bit is copied from the Negotiate
Asymmetric Pause Ability (NAPA) bit in the Flow Control Register. The Next Page,
Acknowledge, and Remote Fault bits are cleared to 0, and the Selector Field is set to 00001 to
indicate IEEE standard 802.3.
5. If this is the first pass through this procedure since EN_PMGR was set to 1, write to the Control
Register (R0) to restart Auto-negotiation.
6. Poll R1 at 1.9 second intervals until the Auto-Negotiation Complete bit is set to 1. If auto-
negotiation is not complete after four polling intervals, go back to step 1.
7. Read the Auto-Negotiation Link Partner Ability Register (R5). Set the MAC's speed, duplex
mode, and pause ability to the highest priority mode that is common to both PHY devices.
8. Poll R1 at 600 ms intervals until the Link Status bit is 1. If Link Status is not found to be 1 after
four polling intervals, go back to step 1.
9. Poll R1 at intervals of about 600 ms until the Link Status bit is 0. Go to step 1.
Table 32.
Sources of Auto-negotiation Advertisement Register (R4) Bits
Bits
4.15
4.14
1000BASE-T Function
Next Page
Reserved
Source of data
R6.2
Cleared to 0