AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 1064

• 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

43.7.5.4
43.7.5.5
43.7.5.6
43.7.5.7
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AT91SAM9G45
Wake-up Triggered by the AC97 Codec
AC97 Codec Reset
Cold AC97 Reset
Warm AC97 Reset
The AC97 Controller can also wake up the AC97 Codec by asserting AC97FS signal, however
this action should not be performed for a minimum period of four audio frames following the
frame in which the powerdown was issued.
This feature is implemented in AC97 modem codecs that need to report events such as Caller-
ID and wake-up on ring.
The AC97 Codec can drive AC97RX signal from low to high level and holding it high until the
controller issues either a cold or a worm reset. The AC97RX rising edge is asynchronously
(regarding AC97FS) detected by the AC97 Controller. If WKUP bit is enabled in AC97C_IMR
register, an interrupt is triggered that wakes up the AC97 Controller which should then immedi-
ately issue a cold or a warm reset.
If the processor needs to be awakened by an external event, the AC97RX signal must be exter-
nally connected to the WAKEUP entry of the system controller.
Figure 43-7. AC97 Power-Down/Up Sequence
There are three ways to reset an AC97 Codec.
A cold reset is generated by asserting the RESET signal low for the minimum specified time
(depending on the AC97 Codec) and then by de-asserting RESET high. AC97CK and AC97FS
is reactivated and all AC97 Codec registers are set to their default power-on values. Transfers
on AC-link can resume.
The RESET signal will be controlled via a PIO line. This is how an application should perform a
cold reset:
AC97CK, the clock provided by AC97 Codec, is detected by the controller.
A warm reset reactivates the AC-link without altering AC97 Codec registers. A warm reset is sig-
naled by driving AC97FX signal high for a minimum of 1us in the absence of AC97CK. In the
• Clear and set ENA flag in the AC97C_MR register to reset the AC97 Controller
• Clear PIO line output controlling the AC97 RESET signal
• Wait for the minimum specified time
• Set PIO line output controlling the AC97 RESET signal
AC97CK
AC97RX
AC97FS
AC97TX
TAG
TAG
Power Down Frame
Write to
Write to
0x26
0x26
Data
Data
PR4
PR4
Sleep State
Wake Event
Warm Reset
TAG
TAG
New Audio Frame
6438F–ATARM–21-Jun-10
Slot1
Slot1
Slot2
Slot2