21 I
2
S
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
21-13
I
2
S Control Register (I2S_CTL)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
I
2
S Control
Register
(I2S_CTL)
0x301400
(16 bits)
D15–9 –
reserved
–
–
–
0 when being read.
D8
DTSIGN
I
2
S signed/unsigned data format
select
1 Signed
0 Unsigned
0
R/W
D7
WCLKMD
I
2
S output word clock mode select 1 L: High
R: Low
0 L: Low
R: High
0
R/W
D6
BCLKPOL I
2
S output bit clock polarity select 1 Negative
0 Positive
0
R/W
D5
DTFORM
I
2
S output data format select
1 LSB first
0 MSB first
0
R/W
D4
I2SOUTEN I
2
S output enable
1 Enable
0 Disable
0
R/W
D3–2 DTTMG[1:0] I
2
S output data timing select
DTTMG[1:0]
Timing mode
0x0 R/W
0x3
0x2
0x1
0x0
reserved
Right justified
Left justified
I
2
S
D1–0 CHMD[1:0] I
2
S output channel mode select
CHMD[1:0]
Channel mode 0x0 R/W
0x3
0x2
0x1
0x0
Mute
Mono left
Mono right
Stereo
Note: All the data transfer conditions must be set using this register before setting I2SSTART/I2S_
START register to start data output from the I
2
S module.
D[15:9] Reserved
D8
DTSIGN: I
2
S Signed/Unsigned Data Format Select Bit
Selects the data format in right justified mode.
1 (R/W): Signed
0 (R/W): Unsigned (default)
Setting DTSIGN to 0 (default) selects the unsigned format. The high-order bits that exceed the valid
data size are set to 0. Setting 1 selects the signed format. The high-order bits that exceed the valid data
size are set to the sign bit value (D15) of the valid data.
This setting is effective only in right justified mode. Set DTSIGN to 0 when another data output timing
mode is selected.
I2S_WS
I2S_SCLK
I2S_SDO
I2S_SDO
(L channel)
(R channel)
0
D15
D2
D1
D0
D14
0
D15 D14
(MSB first, right justified mode, number of bit clock cycles = 18)
D15
D2
D1
D0
D14
D15
D14
DTSIGN = 0 (default)
DTSIGN = 1
7.1 Unsigned and Signed Format
Figure 21.
D7
WCLKMD: I
2
S Output Word Clock Mode Select Bit
Selects the I2S_WS output signal level for indicating a channel.
1 (R/W): High = L channel, Low = R channel
0 (R/W): High = R channel, Low = L channel (default)
I2S_WS0
WCLKMD = 0 (default)
(L channel)
(R channel)
I2S_WS0
WCLKMD = 1
(L channel)
(R channel)
7.2 Word Clock Mode
Figure 21.
D6
BCLKPOL: I
2
S Output Bit Clock Polarity Select Bit
Selects the bit clock polarity.
1 (R/W): Negative
0 (R/W): Positive (default)