LC89052T Datasheet, PDF (24/42 Pages) Sanyo Semicon Device – Digital Audio Interface Receiver

LC89052T
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8._{_}7_{___}U_{___}s_{__}e_{_} r General Definable Output Port ( UGPI )
• UGPI pin is a user-definable output port that can be selected for the following functions.
—Microcontroller interface register output
—Signal output during clock switching transitional period
• Selection is done by GPISEL. The initial setting is set to the microcontroller in_{__}t_{__}e_{_}r_{__}f_{_}a_{__}ce register GPIDAT. However, the
initial setting of this GPIDAT register is "1", so high level is output from the UGPI pin.
8.7.1 Microcontroller interface register out_{_}p_{__}u_{__}t_{___}(_{_}E_{_} xample of signals that control low power of optical module)
• This section describes an example in which UGPI is used as a power supply control signal for an optical module as a
microcontroller _{_}i_{_}n_{__}t_{_}e_{__}r_{_}f_{_}a_{_} ce register output.
(a) Connect the UGPI o_{__}u_{__}t_{_}put to the power supply control switch of the optical module.
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(b) After a reset due to PD, microcontroller interface register output is selected as the initial state of UGPI. As a result,
the default GPIDAT value is output.
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(c) After a reset, the initial value of GPIDAT is set to "1", so H is output from UGPI. Therefore, after a reset, the
control switch is turned off, and data is not supplied from the optical module.
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(d) The application must set GPIDAT to "0" to have the optical module supply data. That is, the UGPI output can be
controlled with GPIDAT, and the current drain can be minimized when the optical module is not used.
LC89052T
UGPI
RXIN
Optical receiver
module
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Figure 8.12 UGPI Output Example (Power supply control signal for an optical module)
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