Samsung S3C2451X User Manual page 656

IIS-BUS INTERFACE
SAMPLING FREQUENCY AND MASTER CLOCK
Master clock frequency (RCLK) can be selected by sampling frequency as shown in Table 25-1. 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 25-1. CODEC clock (CODECLK = 256fs, 384fs, 512fs, 768fs)
8.000
IISLRCK
kHz
(fs)
2.0480
3.0720
CODECLK
(MHz)
4.0960
6.1440
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 25-2
shows the allowable clock frequency mapping relations.
Clock Frequency
BFS 16 fs (10B)
24 fs (11B)
32 fs (00B)
48 fs (01B)
Descriptions
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.
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
25-6
Specifications and information herein are subject to change without notice.
11.025 16.000 22.050
kHz kHz kHz
2.8224 4.0960 5.6448
4.2336 6.1440 8.4672
5.6448 8.1920 11.2900
8.4672 12.2880 16.9340
Table 25-2 IIS clock mapping table
256 fs (00B)
(a)
-
(a) (b)
-
(a) Allowed when BLC is 8-bit (01B)
(b) Allowed when BLC is 16-bit (00B)
(c) Allowed when BLC is 24-bit (10B)
32.000 44.100 48.000
kHz kHz
256fs
8.1920 11.2896 12.2880
384fs
12.2880 16.9344 18.4320
512fs
16.3840 22.5790 24.5760
768fs
24.5760 33.8690 36.8640
RFS
512 fs (01B) 384 fs (10B)
(a)
-
(a) (b)
-
S3C2451X RISC MICROPROCESSOR
64.000 88.200
kHz kHz kHz
16.3840 22.5792
24.5760 33.8688
32.7680 45.1580
49.1520 -
768 fs (11B)
(a)
(a)
(a) (b)
(a) (b) (c) (a) (b) (c)
96.000
kHz
24.5760
36.8640
49.1520
-
(a)
(a)
(a) (b)