cs4215 Cirrus Logic, Inc., cs4215 Datasheet - Page 21

• Manufacturer Part Number: cs4215
• Description: 16-bit Multimedia Audio Codec
• Manufacturer: Cirrus Logic, Inc.

DATA MODE
The data mode is used during conversions to
pass digital data between the CS4215 and exter-
nal devices. The frame sync rate is equal to the
value of the conversion frequency set by the
DFR2-DFR0 bits of the Data Format register.
Each frame has either 64, 128, or 256 bit times
depending on the BSEL bits in the Serial Con-
trol register. Control of gain, attenuation, input
selection and output muting are embedded in the
data stream.
Data Formats
All time slots contain 8 bits. The MSB of the
data is transmitted/received first. The CS4215
data registers have the functions and time slot as-
signments shown in Table 2. The register address
is the time slot number when D/C is 1. The
SDOUT pin goes into a high-impedance state
prior to time slot 1 and after Time Slot 8 (see
Figure 12).
The CS4215 supports four audio data formats:
16-bit 2’s-complement linear, 8-bit unsigned lin-
ear, 8-bit A-Law, and 8-bit
illustrates the transfer characteristic for 16-bit
and 8-bit linear formats. Note that a digital code
DS76F2
TSOUT A,
TSOUT B
FSYNC,
SDOUT
TSIN A
TSIN B
SCLK
SDIN
D/C
_
128
1
Data Mode
Figure 12. Data Mode Timing for 2 CS4215’s
Data from A
-Law. Figure 13
Data to A
2
3
4
64
65 66
Data from B
Data to B
unsigned:
2’s comp:
67 68
16-bit
8-bit
+FS
-FS
-32768
0
69
Time slot
0
Figure 13. Linear Data Formats
1
2
3
4
5
6
7
8
Table 2. Data Registers
128
-16384
65
1
Data from A
Data to A
DIGITAL CODE
Description
Left Audio MS8 bits
Left Audio LS8 bits
Right Audio MS8 bits
Right Audio LS8 bits
Output Setting
Output Setting
Input Setting
Input Setting
2
128
3
0
4
CS4215
16384
191
32767
255
21