Host apparatus and expansion device

Patent metadata

Field	Value
Publication number	US-2017192475-A1
Application number	US-201515325486-A
Country	US
Kind code	A1
Filing date	Apr 14, 2015
Priority date	Jul 15, 2014
Publication date	Jul 6, 2017
Grant date	—

Abstract

An expansion device includes a clock swing detecting unit, a command receiving unit, and a response generating unit. The clock swing detecting unit detects a clock swing set based on a second signal voltage lower than a first signal voltage before the start of initialization. The command receiving unit receives a command having a parameter incorporated that can indicate which signal voltage of the first signal voltage and second signal voltage is being used. The response generating unit responds to the command based on the clock swing.

First claim

1 . An expansion device which is supplied with a power supply voltage from a host and communicates with the host via bus interface signals that are a clock, commands/responses, and data, comprising:
a power supply unit that generates a second power supply voltage from a first power supply voltage provided from outside; an I/O cell unit that can receive or transmit external signals having a first signal voltage or a second signal voltage lower than the first signal voltage; and a command receiving unit that holds a command received via the I/O cell unit from the host; wherein the I/O cell unit includes a power switch unit to supply an I/O cell power with the first voltage or the second voltage lower than the first voltage, wherein until the voltage confirming command is received, the first voltage is supplied to the I/O cell power, and some of input I/O cells are configured to specific threshold, wherein after the voltage confirming command is received, the I/O cell power is selected according to a signal voltage specified by the command, and wherein if the first voltage is supplied to the I/O cell power, an input I/O cell has a threshold for the first signal voltage, and an output I/O cell outputs a signal of the first signal voltage, and if the second voltage is supplied to the I/O cell power, the input I/O cell has a threshold for the second signal voltage, and the output I/O cell outputs a signal of the second signal voltage.

2 . The expansion device according to claim 1 , further comprising:
a response generating unit that returns a result of interpreting the received command as a response via the I/O cell unit to the host; wherein the expansion device receives a voltage identifying command having an argument indicating whether the command transmitted by the host is of the first signal voltage or the second signal voltage and, if supporting the signal voltage level indicated by the argument, selects power supply voltage to the I/O cell power and returns a response having the same signal voltage as the command and, if not supporting the signal voltage level indicated by the argument, does not return the response.

3 . The expansion device according to claim 2 ,
wherein the expansion device switches an threshold voltage of a clock input I/O cell and a command input I/O cell of the I/O cell unit based on the result of a clock voltage detector to be able to receive a command adaptively with the first signal voltage or second signal voltage by controlling input threshold corresponds to clock signal voltage.

4 . The expansion device according to claim 2 ,
wherein until the voltage confirming command is received, the first voltage is supplied to the I/O cell power to have tolerance to the first voltage, and some of input I/O cells are configured to the threshold for second signal voltage to be able to receive both the first signal voltage and the second signal voltage, and wherein after the voltage confirming command is received, the I/O cell power for all I/O cells is selected according to a signal voltage specified by the command, and threshold of all inputs and signal voltage for output are determined according to the voltage supplied to I/O cell power.

5 . The expansion device according to claim 3 ,
wherein the expansion device can initialize with second signal voltage alone without using the first signal voltage, and further comprising: a clock swing detecting unit to detect clock oscillation provided by host; wherein after being supplied the first voltage, the expansion device starts to drive one of data lines to low level by detecting clock oscillation, and the expansion device stops driving of the data line on receiving a command to indicate to host that the expansion device can communicate with second signal voltage alone.

6 . The expansion device according to claim 4 ,
wherein the expansion device can initialize with second signal voltage alone without using the first signal voltage, and further comprising: a clock swing detecting unit to detect clock oscillation provided by host; wherein after being supplied the first voltage, the expansion device starts to drive one of data lines to low level by detecting clock oscillation, and the expansion device stops driving of the data line on receiving a command to indicate to host that the expansion device can communicate with second signal voltage alone.

7 . An expansion device which is supplied with power supply voltages from a host and communicates with the host via interface signals and in which a first power supply voltage with which a memory is operable is supplied via a first power supply terminal and a second power supply voltage with which an interface unit is operable is supplied via a second power supply terminal, wherein the first power supply voltage is higher than or equal to the second power supply voltage,
wherein the interface unit that connects to the host via the interface signals is driven by a power supply unit that generates a third power supply voltage lower than the second power supply voltage and higher than a signal voltage, wherein a controller that controls the expansion device is driven by the power supply unit that generates a fourth power supply voltage lower than the first power supply voltage so that the controller can operate, wherein the power supply unit comprises: a first power supply voltage detecting unit that detects whether the first power supply voltage supplied is a voltage with which the memory is operable; and a second power supply voltage detecting unit that detects whether the second power supply voltage supplied is a voltage with which the interface unit is operable, and wherein if determining that they are operable with power supply of both the first and second power supply voltages, the interface signals indicate that the expansion device can communicate with the host, and if determining that they are not operable, the interface signals indicate that it cannot communicate.

8 - 10 . (canceled)

11 . A host apparatus which comprises a terminal portion that can be connected to an expansion device via a bus interface that supplies and transmits power supply, a clock, commands/responses, and data; and
a front stage that supplies power supply and a clock and can receive a response to an issued command, wherein the front stage sets a signal voltage level based on a second signal voltage lower than a first signal voltage, supplies the clock having the second signal voltage, issues a command having a parameter incorporated indicating the use of the second signal voltage, and ascertains the support of the signal voltage level based on a response result to the command.

12 . The host apparatus according to claim 11 , which waits for a predetermined time until a regulator of the expansion device that generates a second voltage lower than a first power supply voltage from the first power supply voltage becomes stable and then supplies the clock having the second signal voltage and then issues a command having the second signal voltage and can receive a response having the second signal voltage.

13 . The host apparatus according to claim 12 , which determines that the expansion device is usable if receiving a response to a voltage identifying command having an argument indicating that the second signal voltage is being used and determines that the expansion device is unusable if not having received the response.

14 . The host apparatus according to claim 13 , wherein the front stage comprises
a power supply voltage supplying unit that supplies the power supply voltage; and a clock supplying unit that supplies the clock using only the second signal voltage

Assignees

• Toshiba Kk

Inventors

• Fujimoto Akihisa
• Sakamoto Hiroyuki
• Honjo Shinji

Classifications

• G06F1/266 Primary

  Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips · CPC title

• G06F3/061

  Improving I/O performance · CPC title

• G06F1/3287

  by switching off individual functional units in the computer system · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F13/4282

  on a serial bus, e.g. I2C bus, SPI bus (on daisy chain buses G06F13/4247) · CPC title