WM8281ECSSLASHR datasheet(241/392 Pages) CIRRUS

241 / 392 page

WM8281

Rev 4.0

241

ISOCHRONOUS SAMPLE RATE CONVERTER (ISRC) CONFIGURATION ERROR

STATUS OUTPUT

GPn_FN = 4Dh, 4Eh, 4Fh.

The WM8281 performs automatic checks to confirm that the ISRCs are configured with valid settings.

Invalid settings include conditions where an invalid combination of sample rates is configured. If an

invalid ISRC configuration is detected, this can be indicated using the GPIO and/or Interrupt functions.

The ISRC Configuration Error signal may be output directly on a GPIO pin by setting the respective

GPIO registers as described in “GPIO Control”.

The ISRC Configuration Error signals are inputs to the Interrupt Controller circuit. An interrupt event is

triggered on the rising edge of the ISRC Configuration Error signals. The associated interrupt bits are

latched once set; they

can be polled at any time or used to control the IRQ signal. See “Interrupts” for

more details of the Interrupt event handling.

OVER-TEMPERATURE, SHORT CIRCUIT PROTECTION, AND SPEAKER SHUTDOWN

STATUS OUTPUT

GPn_FN = 2Bh, 2Ch, 53h, 54h, 55h, 56h, 57h, 58h, 59h, 5Ah, 5Bh, 5Ch, 5Dh, 5Eh, 5Fh, 60h, 61h.

The WM8281 incorporates a temperature sensor which detects when the device temperature is within

normal limits or if the device is approaching a hazardous temperature condition.

The temperature status may be output directly on a GPIO pin by setting the respective GPIO registers

as described in “GPIO Control”. A GPIO pin can be used to indicate either an Overheat Warning

Temperature event or an Overheat Shutdown Temperature event.

The WM8281 provides short circuit protection on the Class D speaker outputs, and on each of the

headphone output paths.

The status of each of the short circuit detection circuits may be output directly on a GPIO pin by

setting the respective GPIO registers as described in “GPIO Control”.

Note that two short circuit indications are implemented for each headphone output channel (relating to

detection in the positive and negative output voltage regions respectively); if either of these indications

is asserted, then a short circuit condition exists in the respective output path.

If the Overheat Shutdown Temperature is exceeded, or if a short circuit is detected on the Class D

speaker outputs, then the Class D speaker outputs will automatically be disabled in order to protect

the device. When the speaker driver shutdown is complete, the Speaker Shutdown signal will be

asserted. The speaker driver shutdown status can also be output directly on a GPIO pin.

The Overtemperature, Short Circuit protection, and Speaker Shutdown status flags are inputs to the

Interrupt control circuit. An interrupt event may be triggered on the applicable edges of these signals.

The associated interrupt bit is latched once set; it can be polled at any time or used to control the IRQ

signal. See “Interrupts” for more details of the Interrupt event handling.

WM8281ECS/R Scheda tecnica(PDF) 241 Page - Cirrus Logic