82NM10 Datasheet, PDF (83/671 Pages) Intel Corporation – Intel® NM10 Family Express Chipset

Functional Description
5.2.4
5.2.4.1
5.2.4.2
Hot-Plug
Each root port implements a Hot-Plug controller which performs the following:
• Messages to turn on / off / blink LEDs
• Presence and attention button detection
• Interrupt generation
The root port only allows Hot-Plug with modules (e.g., ExpressCard*). Edge-connector
based Hot-Plug is not supported.
Presence Detection
When a module is plugged in and power is supplied, the physical layer will detect the
presence of the device, and the root port sets SLSTS.PDS (D28:F0/F1/F2/F3:Offset
5Ah:bit 6) and SLSTS.PDC (D28:F0/F1/F2/F3:Offset 6h:bit 3). If SLCTL.PDE (D28:F0/
F1/F2/F3:Offset 58h:bit 3) and SLCTL.HPE (D28:F0/F1/F2/F3:Offset 58h:bit 5) are
both set, the root port will also generate an interrupt.
When a module is removed (via the physical layer detection), the root port clears
SLSTS.PDS and sets SLSTS.PDC. If SLCTL.PDE and SLCTL.HPE are both set, the root
port will also generate an interrupt.
Message Generation
When system software writes to SLCTL.AIC (D28:F0/F1/F2/F3:Offset 58h:bits 7:6) or
SLCTL.PIC (D28:F0/F1/F2/F3:Offset 58h:bits 9:8), the root port will send a message
down the link to change the state of LEDs on the module.
Writes to these fields are non-postable cycles, and the resulting message is a postable
cycle. When receiving one of these writes, the root port performs the following:
• Changes the state in the register.
• Generates a completion into the upstream queue
• Formulates a message for the downstream port if the field is written to regardless
of if the field changed.
• Generates the message on the downstream port
• When the last message of a command is transmitted, sets SLSTS.CCE (D28:F0/F1/
F2/F3:Offset 58h:bit 4) to indicate the command has completed. If SLCTL.CCE and
SLCTL.HPE (D28:F0/F1/F2/F3:Offset 58h:bit 5) are set, the root port generates an
interrupt.
The command completed register (SLSTS.CC) applies only to commands issued by
software to control the Attention Indicator (SLCTL.AIC), Power Indicator (SLCTL.PIC),
or Power Controller (SLCTL.PCC). However, writes to other parts of the Slot Control
Register would invariably end up writing to the indicators, power controller fields;
Hence, any write to the Slot Control Register is considered a command and if enabled,
Datasheet
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