AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 1060

• Manufacturer Part Number: AT91SAM9G45-EKES
• Description: KIT EVAL FOR AT91SAM9G45
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91SAM9G45-EKES

• Contents: Board
• Processor To Be Evaluated: SAM9G45
• Data Bus Width: 32 bit
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 50 C
• Minimum Operating Temperature: - 10 C
• Operating Supply Voltage: 1.8 V to 3.3 V
• For Use With/related Products: AT91SAM9G45
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q4626953

Figure 43-6. Audio Transfer (PCM L Front, PCM R Front) on Channel x
43.7.3.5
43.7.3.6
1060
Read access to
(Codec output)
AC97C_RHRx
(AC97C_SR)
RXRDYCx
AC97RX
AC97FS
AT91SAM9G45
Slot #
AC97 Input Frame
Configuring and Using Interrupts
TAG
0
The application can also wait for an interrupt notice in order to read data from AC97C_CxRHR.
The interrupt remains active until RXRDY is cleared by reading AC97C_CxSR.
The RXRDY flag in AC97C_CxSR is set automatically when data is received in the Channel x
shift register. Data is then shifted to AC97C_CxRHR.
If the previously received data has not been read by the application, the new data overwrites the
data already waiting in AC97C_CxRHR, therefore the OVRUN flag in AC97C_CxSR is raised.
The application can either poll the OVRUN flag in AC97C_CxSR or wait for an interrupt notice.
The interrupt remains active until the OVRUN flag in AC97C_CxSR is set.
The AC97 Controller can also be used in sound recording devices in association with an AC97
Codec. The AC97 Controller may also be exposed to heavy PCM transfers. The application can
use the PDC connected to channel A in order to reduce processor overhead and increase per-
formance especially under an operating system.
The PDC receive counter values must be equal to the number of PCM samples to be received,
each sample goes in one slot.
The AC97 Controller receives a thirteen slot frame on the AC-Link sent by the AC97 Codec. The
first slot (tag slot or slot 0) flags the validity of the entire frame and the validity of each slot;
whether a slot carries valid data or not. Slots 1 and 2 are used if the application requires status
informations from AC97 Codec. Slots [3:12] are used according to AC97 Controller Output
Channel Assignment Register (AC97C_ICA) content. The AC97 Controller will not receive any
data from any slot if AC97C_ICA is not assigned to a channel in input.
Instead of polling flags in AC97 Controller Global Status Register (AC97C_SR) and in AC97
Controller Channel x Status Register (AC97C_CxSR), the application can wait for an interrupt
notice. The following steps show how to configure and use interrupts correctly:
The interrupt handler must read both AC97 Controller Global Status Register (AC97C_SR) and
AC97 Controller Interrupt Mask Register (AC97C_IMR) and AND them to get the real interrupt
source. Furthermore, to get which event was activated, the interrupt handler has to read AC97
Controller Channel x Status Register (AC97C_CxSR), x being the channel whose event triggers
the interrupt.
STATUS
• Set the interruptible flag in AC97 Controller Channel x Mode Register (AC97C_CxMR).
• Set the interruptible event and channel event in AC97 Controller Interrupt Enable Register
ADDR
(AC97C_IER).
1
STATUS
DATA
2
LEFT
3
PCM
RIGHT
4
PCM
LINE 1
DAC
5
6
PCM
MIC
RSVED
7
RSVED
8
RSVED
9
LINE 2
ADC
10
6438F–ATARM–21-Jun-10
HSET
11
ADC
STATUS
12
IO