21 I
2
S
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
21-3
4.1 I2S_MCLK (Master Clock) Settings
Table 21.
MCLKDIV[5:0]
PCLK1 division ratio
0x3f
1/64
0x3e
1/63
0x3d
1/62
:
:
0x2
1/3
0x1
1/2
0x0
1/1
(Default: 0x0)
Division ratio for I2S_SCLK (bit clock)
The I
2
S module generates the bit clock to be output from the I2S_SCLK pin by dividing PCLK1.
Specify the division ratio using BCLKDIV[7:0]/I2S_DV_AUDIO_CLK register.
4.2 I2S_SCLK (Bit Clock) Settings
Table 21.
BCLKDIV[7:0]
PCLK1 division ratio
0xff
1/512
0xfe
1/510
0xfd
1/508
:
:
0x2
1/6
0x1
1/4
0x0
1/2
(Default: 0x0)
The I
2
S bit clock frequency is calculated as below.
f
PCLK1
f
I2S_SCLK
= ————————— [Hz]
(B 1)
×
2
f
I2S_SCLK
: I
2
S bit clock frequency [Hz]
f
PCLK1
:
PCLK1 clock frequency [Hz]
BCLKDIV: BCLKDIV[7:0] set value (0x0–0xff)
Sample clock (I2S_WS) period
The I
2
S generates the sample clock (word-select clock) to be output from the I2S_WS pin by counting the
bit clock configured with BCLKDIV[7:0]. Specify the half cycle (a high or low level period) of the I2S_
WS clock with the number of bit clock cycles using WSCLKCYC[4:0]/I2S_DV_AUDIO_CLK register.
4.3 Sample Clock Period Settings
Table 21.
WSCLKCYC[4:0]
Sample clock period
(number of bit clock cycles)
0x1f–0x11
Reserved
0x10
32 clocks
0xf
31 clocks
0xe
30 clocks
0xd
29 clocks
0xc
28 clocks
0xb
27 clocks
0xa
26 clocks
0x9
25 clocks
0x8
24 clocks
0x7
23 clocks
0x6
22 clocks
0x5
21 clocks
0x4
20 clocks
0x3
19 clocks
0x2
18 clocks
0x1
17 clocks
0x0
16 clocks
(Default: 0x0)