Preliminary
IIS MULTI AUDIO INTERFACE
S3C2451X RISC MICROPROCESSOR
26-6
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
SAMPLING FREQUENCY AND MASTER CLOCK
Master clock frequency (RCLK) can be selected by sampling frequency as shown in
Table 26-
1. Because RCLK
is made by IIS pre-scaler, the pre-scaler value and RCLK type (256fs or 384fs or 512fs or 768fs) should be
determined properly.
Table 26-1. CODEC clock (CODECLK = 256fs, 384fs, 512fs, 768fs)
IISLRCK
(fs)
8.000
kHz
11.025
kHz
16.000
kHz
22.050
kHz
32.000
kHz
44.100
kHz
48.000
kHz
64.000
kHz
88.200
kHz
96.000
kHz
256fs
2.0480 2.8224
4.0960 5.6448
8.1920
11.2896
12.2880
16.3840 22.5792
24.5760
384fs
CODECLK
3.0720 4.2336
6.1440 8.4672
12.2880
16.9344
18.4320
24.5760 33.8688
36.8640
(MHz)
512fs
4.0960
5.6448
8.1920
11.2900
16.3840
22.5790
24.5760
32.7680 45.1580
49.1520
768fs
6.1440
8.4672
12.2880
16.9340
24.5760
33.8690
36.8640
49.1520 -
-
Note
: fs represents sampling frequency.
CODECLK Frequency = fs * (256 or 384 or 512 or 768)
IIS CLOCK MAPPING TABLE
On selecting BFS, RFS, and BLC bits of I2SMOD register, user should refer to the following table.
Table 26-
2
shows the allowable clock frequency mapping relations.
Table 26-2 IIS clock mapping table
RFS
Clock Frequency
256 fs (00B)
512 fs (01B)
384 fs (10B)
768 fs (11B)
16 fs (10B)
(a) (a) (a) (a)
24 fs (11B)
- - (a)
(a)
32 fs (00B)
(a) (b)
(a) (b)
(a) (b)
(a) (b)
BFS
48 fs (01B)
-
-
(a) (b) (c)
(a) (b) (c)
Descriptions
(a) Allowed when BLC is 8-bit (01B)
(b) Allowed when BLC is 16-bit (00B)
(c) Allowed when BLC is 24-bit (10B)
Note
: Bit Clock Frequency
≥
fs * (bit length * 2). Under this condition Bit Clock Frequency can be one of among
fs * (16 or 24 or 32 or 48). The codec clock is a multiple of the bit clock among fs * (256 or 384 or 512 or 768)
Example
: If bit length is 16 bit, Bit Clock Frequency
≥
fs * 32. So it can be one of fs * (32 or 48).
If Bit Clock Frequency is 48 fs, then 384fs(48 fs* 8) and 768fs(48 fs * 16) are the clock which is a
multiple of the Bit Clock Frequency.