OVERVIEW
The 88SM4140 is a Serial ATA (SATA) Port Multiplier (PM) that allows an active host connection to communicate with up to four device ports and one SEMB port. The 88SM4140 is used to consolidate the capacity of storage devices by allowing a single host SATA port to be connected to more than one SATA device. This port multiplier employs Marvell’s SATA 3.0 Gbps Physical Layer (Phy) technology.

FEATURES
General
■ 0.15 µm CMOS technology.
■ Supports SATA 1.5 Gbps and SATA 3.0 Gbps communication speed on host and device ports.
■ 1.2V and 3.3V power.
■ 80-pin LQFP ePad package.
■ Phy test mode.
■ Full scan for high production test coverage and Phy self-test.
■ One host port.
■ Four device ports.
■ Supports 20 MHz, 25 MHz, 30 MHz, and 40 MHz reference clocks.

Functional
The 88SM4140 supports the following features:
■ Issuing PMREQP to host.
■ 57600 bps UART access.
■ Spread-spectrum clocking transmission.
■ Serial ATA BIST over host and device links.
■ Asynchronous notification.
■ SAF-TE (Enclosure Management).
■ FIS-based switching in conjunction with the following Marvell SATA host controllers:
   ■ 88SX6042
   ■ 88SX7042
   ■ 88SE6145
   ■ 88SE6121
■ Marvell Specific Mode (optional).
   ■ Queued command-based switching mode for Marvell 88SX6041 and 88SX6081.
■ One SEMB port/SM bus port (optional).