Semiconductor integrated circuit device

Abstract

A semiconductor integrated circuit device is disclosed that includes a signal processing unit having a nonvolatile memory and a detection unit; plural oscillation sources outputting plural oscillation signals; a selection control unit that selects one of the oscillation signals output by the oscillation sources according to a selection signal, and controls a transfer timing for transferring circuit setting information from the nonvolatile memory to the detection unit and an operations start timing for starting signal processing operations of the signal processing unit according to the selected oscillation signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram of a signal processing circuit device according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of a selection control circuit of the signal processing circuit device shown in FIG. 1;

FIG. 3 is a diagram illustrating operations when a first oscillation signal is selected;

FIG. 4 is a diagram illustrating operations when a second oscillation signal is selected;

FIG. 5 is a circuit diagram of a battery pack that uses a signal processing circuit device according to an embodiment of the present invention;

FIG. 6 is a circuit diagram of a portable electronic device using the battery pack shown in FIG. 5; and

FIG. 7 is a diagram illustrating oscillation signals output by an internal oscillator circuit and a crystal oscillator circuit.

Claims

1. A semiconductor integrated circuit device, comprising: a signal processing unit including a nonvolatile memory and a detection unit;a plurality of oscillation sources outputting a plurality of oscillation signals;a selection control unit that-selects one of the oscillation signals output by the oscillation sources according to a selection signal, and controls a transfer timing for transferring circuit setting information from the nonvolatile memory to the detection unit and an operations start timing for starting signal processing operations of the signal processing unit according to the selected oscillation signal.

2. The semiconductor integrated circuit device as claimed in claim 1, further comprising: a power-on reset unit that detects a power-on status and resets the signal processing unit; whereinthe selection control unit determines the transfer timing and the operations start timing based on reset operations of the power-on reset unit.

3. The semiconductor integrated circuit device as claimed in claim 2, wherein the oscillation sources include a first oscillation output unit that is integrated into a semiconductor integrated circuit and a second oscillation output unit that uses an external crystal oscillating element.

4. The semiconductor integrated circuit device as claimed in claim 3, wherein the selection control unit includes a selection unit that selects one of a first oscillation signal output by the first oscillation output unit or a second oscillation signal output by the second oscillation output unit according to the selection signal;a first counter that inputs said one of the first oscillation signal or the second oscillation signal selected by the selection unit and counts to a first time period that is required for transferring the circuit setting information;a second counter that inputs said one of the first oscillation signal or the second oscillation signal selected by the selection unit and counts to a second time period that is required for stabilizing the second oscillation signal; anda third counter that inputs said one of the first oscillation signal or the second oscillation signal selected by the selection unit and counts to a third time that is obtained by subtracting the first time period from the second time period; whereinwhen the first oscillation signal is selected, the selection control unit controls the transferring of the circuit setting information to start when the power-on reset unit resets the signal processing unit, and controls the signal processing operations of the signal processing unit to start after the first time period elapses from the transfer start timing; andwhen the second oscillation signal is selected, the selection control unit controls the transferring of the circuit setting information to start after the third time period elapses from the time the power-on reset unit resets the signal processing unit, and controls the signal processing operations of the signal processing unit to start after the second time period elapses from the time the power-on reset unit resets the signal processing unit.

5. The semiconductor integrated circuit device as claimed in claim 1, wherein the selection signal is supplied from an external source.

6. The semiconductor integrated circuit device as claimed in claim 1, wherein the signal processing unit includes a register that stores the selection signal.