INEN (AMUTE.3)
1
0
INPOL bit
(AMUTE.2)
AMUTEIN
pin
AMUTEIN pin
allows chaining of
errors detected
by external device
(DIR) with internally
detected errors
ROVRN (RSTAT.0)
ROVRN (AMUTE.5)
XUNDRN (XSTAT.0)
XUNDRN (AMUTE.6)
RSYNCERR (RSTAT.1)
RSYNCERR (AMUTE.7)
XSYNCERR (XSTAT.1)
XSYNCERR (AMUTE.8)
RCKFAIL (RSTAT.2)
RCKFAIL (AMUTE.9)
XCKFAIL (XSTAT.2)
XCKFAIL (AMUTE.10)
RDMAERR (RSTAT.7)
RDMAERR (AMUTE.11)
XDMAERR (XSTAT.7)
XDMAERR (AMUTE.12)
OR
MUTEN bit
(AMUTE[1−0])
Error is detected (and enabled)
Drives AMUTE pin
AMUTE
pin
Functional Description
•
In the transmit status register (XSTAT):
–
Transmit underrun (XUNDRN).
–
Unexpected transmit frame sync (XSYNCERR).
–
Transmit clock failure (XCKFAIL).
–
Transmit DMA error (XDMAERR).
Each interrupt source also has a corresponding enable bit in the receive interrupt control register
(RINTCTL) and transmit interrupt control register (XINTCTL). If the enable bit is set in RINTCTL or
XINTCTL, an interrupt is requested when the interrupt flag is set in RSTAT or XSTAT. If the enable bit is
not set, no interrupt request is generated. However, the interrupt flag may be polled.
22.3.13.5 Audio Mute (AMUTE) Function
The McASP includes an automatic audio mute function (
) that asserts in hardware the
AMUTE pin to a preprogrammed output state, as selected by the MUTEN bit in the audio mute control
register (AMUTE). The AMUTE pin is asserted when one of the interrupt flags is set or an external device
issues an error signal on the AMUTEIN input. Typically, the AMUTEIN input is shared with a device
interrupt pin (for example EXT_INT4).
The AMUTEIN input allows the on-chip logic to consider a mute input from other devices in the system, so
that all errors may be considered. The AMUTEIN input has a programmable polarity to allow it to adapt to
different devices, as selected by the INPOL bit in AMUTE, and it must be enabled explicitly.
In addition to the external AMUTEIN input, the AMUTE pin output may be asserted when one of the error
interrupt flags is set and its mute function is enabled in AMUTE.
When one or more of the errors is detected and enabled, the AMUTE pin is driven to an active state that
is selected by MUTEN in AMUTE. The active polarity of the AMUTE pin is programmable by MUTEN (and
the inactive polarity is the opposite of the active polarity). The AMUTE pin remains driven active until
software clears all the error interrupt flags that are enabled to mute, and until the AMUTEIN is inactive.
Figure 22-35. Audio Mute (AMUTE) Block Diagram
3822
Multichannel Audio Serial Port (McASP)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated