CC2510_15 Datasheet, PDF (160/245 Pages) Texas Instruments – Low-Power SoC (System-on-Chip) with MCU, Memory,2.4 GHz RF Transceiver, and USB Controller

CC2511F8 - Not Recommended for New Designs
located in the I2SSTAT register. The interrupt
enables and flags are summarized below.
Interrupt enable bits:
• I²S RX: I2SCFG0.RXIEN
• I²S TX: I2SCFG0.TXIEN
Interrupt flags:
• I²S RX: I2SSTAT.RXIRQ
• I²S TX: I2SSTAT.TXIRQ
The TX interrupt flag I2SSTAT.TXIRQ is
asserted together with IRCON2.I2STXIF
when the internal TX buffer is empty and the
I²S fetches the new data previously written to
the I2SDATH:I2SDATL registers. The TX
interrupt flag, I2SSTAT.TXIRQ, is cleared
when I2SDATH register is written. An interrupt
request is only generated when
I2SCFG0.TXIEN and IEN2.I2STXIE are
both set to 1.
The RX interrupt flag I2SSTAT.RXIRQ is
asserted together with TCON.I2SRXIF when
the internal RX buffer is full and the contents of
the RX buffer is copied to the pair of internal
data registers that can be read from the
I2SDATH:I2SDATL registers. The RX
interrupt flag, I2SSTAT.RXIRQ, is cleared
when the I2SDATH register is read. An
interrupt request is only generated when
I2SCFG0.RXIEN and IEN0.I2SRXIE are
both set to 1.
Notice that interrupts will also be generated if
the corresponding RXIRQ or TXIRQ flags are
set from software, given that the interrupts are
enabled.
The I²S shares interrupt vector with USART 1,
and the ISR must take this into account if both
modules are used. Refer to Section 1.1 on
Page 57 for more details about interrupts.
12.15.3 I²S DMA Triggers
There are two DMA triggers associated with
the I²S interface, I2SRX and I2STX. The DMA
triggers are activated by RX complete and TX
complete events, i.e. the same events that can
generated the I²S interrupt requests. The DMA
triggers are not masked by the interrupt enable
bits, I2SCFG0.RXIEN and I2SCFG0.TXIEN,
hence a DMA channel can be configured to
use the I²S receive/transmit data registers,
I2SDATH:I2SDATL, as source or destination
address and let RX and TX complete trigger
the DMA.
CC2510Fx / CC2511Fx
Notice that the DMA triggers I2SRX and
ADC_CH6 share the same DMA trigger
number (# 27) in the same way as I2STX and
ADC_CH7 share DMA trigger number 28. This
means that I2SRX can not be used together
with ADC_CH6 and I2STX can not be used
together with ADC_CH7. On the CC2511Fx ADC
channels 6 and 7 cannot be used since P0_6
and P0_7 I/O pins are not available.
Refer to Table 51 on Page 104 for an overview
of the DMA triggers.
12.15.4 Underflow/Overflow
If the I²S attempts to read from the internal TX
buffer when it is empty, an underflow condition
occurs. The I²S will then continue to read from
the data in the TX buffer, and
I2SSTAT.TXUNF will be asserted.
If the I²S attempts to write to the internal RX
buffer while it is full, an overflow condition
occurs. The contents of the RX buffer will be
overwritten and the I2SSTAT.RXOVF flag will
be asserted.
Thus, when debugging an application,
software may check for underflow/overflow
when an interrupt is generated or when the
application completes. The TXUNF / RXOVF
flags should be cleared in software.
12.15.5 Writing a Word (TX)
When each sample fits into a single byte or µ-
Law compressed samples (always 8 bits) are
written, i.e. µ-Law expansion is enabled
(I2SCFG0.ULAWE=1), only the I2SDATH
register needs to be written.
When each sample is more than 8 bits the low
byte must be written to the I2SDATL register
before the high byte is written to the I2SDATH
register, hence writing the I2SDATH register
indicates the completion of the write operation.
When the I²S is configured to send stereo, i.e.
I2SCFG0.TXMONO is 0, the I2SSTAT.TXLR
flag can be used to determine whether the left-
or right-channel sample is to be written to the
data registers.
12.15.6 Reading a Word (RX)
If each sample fits into a single byte or if µ-Law
compression is enabled (I2SCFG0.ULAWC=1),
only the I2SDATH register needs to be read.
When each sample is more than 8 bits the low
byte must be read from the I2SDATL register
before the high byte is being read from the
SWRS055G
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