CS5535 datasheet(85/555 Pages) NSC

85 / 555 page

ACC Functional Description (Continued)

www.national.com

Revision 0.8

Slot 12: GPIO Control

This slot allows the ACC to set the value of the AC97

codec’s GPIO output pins.

bits [19:4]

Value of the GPIO pins

(Up to 16 can be implemented)

bits [3:0]

Reserved

4.3.4.3

AC Link Input Frame (AC_S_IN, AC_S_IN2)

The audio input frame data streams correspond to the time

division multiplexed bundles of all digital input data coming

from the AC97 codec. Each input frame contains 13, 20-bit

incoming data slots, except for slot 0; it is 16 bits. Slot 0 is a

dedicated slot used for the AC Link protocol.

An audio input frame begins with a low-to-high transition of

the AC_S_SYNC signal. AC_S_SYNC is synchronous to

the rising edge of AC_CLK. The AC97 codec samples the

AC_S_SYNC signal on the immediately following falling

edge of the bit clock. The AC97 codec transmits data on

each following rising edge of AC_CLK. The ACC samples

the data on the falling edges of AC_CLK.

The serial input stream is MSB justified (MSB first) within

each slot, and all non-valid bit positions stuffed with zeroes

by the AC97 codec.

Slot 0: TAG

The first bit of the TAG slot (bit 15) is the Codec_Ready bit.

The next 12 bits indicate the validity of the next 12 data

slots.

Slot 1: Status Address / SLOTREQ Bits

The status address is the echo of the register address

(index) that was sent to the codec on output slot 1 of the

previous output frame. It indicates the address (index) of

the register whose data is being returned in slot 2 of the

input frame.

bit 19

Reserved

(Stuffed with 0s)

bits [18:12]

Control Register Index

(Echo of register index for which data

is being returned)

bits [11:2]

SLOTREQ bits

(For variable sampling rate)

bits [1:0]

Reserved

(Stuffed with 0s)

The SLOTREQ bits support the variable sample rate sig-

naling protocol. With normal 48 kHz operation, these bits

are always zero. When the AC97 codec is configured for a

lower sample rate, some output frames will not contain

samples because the AC Link always outputs frames at 48

kHz. The SLOTREQ bits serve as the codec’s instrument to

tell the ACC whether it needs a sample for a given slot on

the next output frame. For each bit: 0 = Send data; 1 = Do

NOT send data. If the codec does not request data for a

given slot, the ACC should tag that slot invalid and not send

PCM data. The mapping between SLOTREQ bits and out-

put slots is given in Table 4-5. The SLOTREQ bits are inde-

pendent of the validity of slot 1, and slot 1 will only be

tagged valid by the codec if it contains a register index.

Slot 2: Status Data

The status data slot delivers 16-bit control register read

data.

bits [19:4]

Control Register Read Data

(Stuffed with 0s if slot 2 is tagged

“invalid” by slot 0)

bits [3:0]

Reserved

(Stuffed with 0s)

Slot 3: PCM Record Left Channel

Contains the left channel ADC input data (16-bit resolution,

MSB first, unused LSBs = 0).

Slot 4: PCM Record Right Channel

Contains the right channel ADC input data (16-bit resolu-

tion, MSB first, unused LSBs = 0).

Slot 5: Modem Line 1 ADC

Contains the modem line 1 ADC input data (16-bit resolu-

tion, MSB first, unused LSBs = 0).

Slot 6: Optional Microphone Record Data

Contains the microphone ADC input data (16-bit resolution,

MSB first, unused LSBs = 0).

Slots 7-10: Not Used

Slots 7-10 are reserved.

Slot 11: Modem Headset ADC

Contains the modem headset ADC input data (16-bit reso-

lution, MSB first, unused LSBs = 0).

Table 4-5. SLOTREQ to Output Slot Mapping

Bit

Slot

Request

Notes

Slot 3

Left Channel Out (BM0)

Slot 4

Right Channel Out (BM0)

Slot 5

Modem Line 1 Out (BM2)

Slot 6

Center Out (BM4 if selected)

Slot 7

Left Surround Out (BM6)

Slot 8

Right Surround Out (BM6)

Slot 9

LFE Out (BM7)

Slot 10

Not Supported

Slot 11

Handset Out (BM4 if selected)

Slot 12

Not Supported

CS5535 Scheda tecnica(PDF) 85 Page - National Semiconductor (TI)

CS5535 Scheda tecnica(HTML) 85 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Scheda tecnica Scarica

Link URL