SI2438FT18-EVB Silicon Laboratories Inc, SI2438FT18-EVB Datasheet - Page 44

• Manufacturer Part Number: SI2438FT18-EVB
• Description: BOARD EVAL SI2438+SI3018 24PIN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2438FT18-EVB

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Si3050 + Si3011/18/19
5.33. Companding in PCM Mode
The Si3050 supports both µ-Law and A-Law companding formats in addition to 16-bit linear data. The 8-bit
companding schemes follow a segmented curve formatted as a sign bit, three chord bits, and four step bits. µ-Law
is commonly used in North America and Japan, while A-Law is primarily used in Europe. Data format is selected
via the PCMF bits (Register 33). Table 22 on page 45 and Table 23 on page 46 define the µ-Law and A-Law
encoding formats. If linear mode is used the resulting 16-bit data is transmitted in two consecutive 8-bit PCM
highway timeslots as shown in Figure 34.
5.34. 16 kHz Sampling Operation in PCM Mode
The Si3050 can be configured to support a 16 kHz sampling rate and transmit the data on an 8 kHz PCM or GCI
highway bus. By setting the HSSM bit (Register 7, bit 3) to 1, the DAA changes its sampling rate, Fs, to 16 kHz if it
was originally configured for an 8 kHz sampling rate. If µ-law or A-law companding is used, the resulting 8-bit
samples are transmitted in two consecutive 8-bit PCM highway timeslots. If linear mode is used, the resulting 16-bit
samples are transmitted in four consecutive 8-bit PCM highway timeslots as shown in Figure 35.
44
PCLK_CNT
FSYNC
PCLK
DRX
DTX
PCLK_CNT
Figure 34. PCM Highway Transmission, Single Clock Cycle, 16-bit linear mode
Figure 35. PCM Highway Transmission, Single Clock Cycle, 16-bit linear mode
HI-Z
0
FSYNC
PCLK
MSB
MSB
DRX
DTX
1
2
HI-Z
3
(TXS = RXS = 0, PHCF = 0, TRI = 1, PCMF = 11, HSSM = 1)
4
5
0
6
(TXS = RXS = 0, PHCF = 0, TRI = 1, PCMF = 11)
MSB
Sample 1
MSB
7
1
8
2
9
10
3
11
12
4
13
5
14
15
6
16
Rev. 1.4
7
17
18
8
19 20
9
21
10
22
Sample 2
23
11
24
12
25
HI-Z
26
13
27
14
28
29
15
30
LSB
LSB
31
16
LSB
LSB
32
17
33
34
HI-Z
18
35
36 37