Sata Data Plug

SATA uses a point-to-point architecture.

SATA defines multipliers, which allows a single SATA controller port to drive up to fifteen storage devices.

Physical layer -> Link layer  -> Transport layer

Use of 8b/10b encoding

DC-balanced which allows the signals to be AC-coupled.

point-to-point AC-coupled low-voltage differential signaling (LVDS) links are used for physical transmission between host and drive.

the actual SATA signalling is half-duplex, meaning that it can only read or write data at any one time.

SATA 插頭

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1     7     # 直角位是 7

Cable

Cable 內共有兩組(pair) shielded cable. Data A 一組(transmit pair), Data B 一組(receive pair)

Pin

• 1     Ground
• 2     A+ (transmit+)
• 3     A− (transmit-)
• 4     Ground
• 5     B− (receive+)
• 6     B+ (receive-)
• 7     Ground

Power

此 port 有 3.3V, 5V 及 12V 供電

 * Each voltage is supplied by three pins

Diagram

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15     1

 * 它與  data port 係相反 pinout (1在L底)

Pin

• 1,2,3        3.3V (orange)
• 4,5,6        Gnd (black)
• 7,8,9        5V (red)
• 10            Gnd (black)
• 11            Staggered spinup/activity (Optional)
• 12            Gnd (black)
• 13,14,15  12V (yellow)

Currently, SATA drives rarely use 3.3 volts. (Pins 1, 2, and 3 are optional)

 * Each pin should be able to carry 1.5 A

One pin in each group(3.3V, 5V, 12V) is intended for precharging

[1] 4 and 12 in a hot-swap cable are the longest, so they make contact first when the connectors are mated.

[2] Drive power connector pins 3, 7, and 13 are longer than the others, so they make contact next.

      (The drive uses them to charge its internal bypass capacitors through current-limiting resistances)

[3] remaining power pins make contact, bypassing the resistances

原因

Molex 4-pin Power Connector

• 1 Yellow     +12 V
• 2,3 Black     Ground
• 4  Red        +5 V

Plug(female = 金屬圈)

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  ||
/1234\

Staggered spin-up (SSU)[Pin 11]

It is an open-collector signal, which may be pulled down by the connector or the drive.

 -  can be employed to prevent the excessive power-consumption of spin-up

 -  starts one drive at a time, either waiting for the drive to signal it is ready or allowing a predefined period of time to pass before starting the next drive.

 - it does not require any special commands to get the drive to spin-up.

過程

When the drive is initially powered on, the drive senses whether Pin 11 is left floating (high or '1' logic state) or grounded (low or '0' logic state)

SSU is disabled when Pin 11 is grounded

Ground => When disabled, the drive will spin-up as soon as power is applied to it.

SSU is enabled when Pin 11 is left floating or driven high (high or '1' logic state).

Floating / Driven high => The drive will not spin-up until the SATA Phy Interface becomes active with a connection to a SATA controller

The pin is also pulled low by the drive to indicate drive activity. This may be used to give feedback to the user through an LED.