21 I
2
S
21-18
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
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)
I
2
S Start/Stop Register (I2S_START)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
I
2
S Start/Stop
Register
(I2S_START)
0x301408
(16 bits)
D15–8 –
reserved
–
–
–
0 when being read.
D7
I2SBUSY
I
2
S busy flag
1 Busy
0 Idle
0
R
D6–1 –
reserved
–
–
–
0 when being read.
D0
I2SSTART
I
2
S start/stop control
1 Start (run)
0 Stop
0
R/W
D[15:8] Reserved
D7
I2SBUSY: I
2
S Busy Flag Bit
Indicates the data output status of the I
2
S module.
1 (R):
Busy
0 (R):
Idle (default)
I2SBUSY is set to 1 when 1 is written to I2SSTART and stays 1 while data is being output. This flag is
cleared to 0 upon completion of the output operation.
D[6:1]
Reserved
D0
I2SSTART: I
2
S Start/Stop Control Bit
Starts/stops data output of the I
2
S.
1 (R/W): Start
0 (R/W): Stop (default)
Writing 1 to I2SSTART starts serial data transmission through the I2S_SDO pin.
Writing 0 to I2SSTART stops data transmission. Note, however, that the data currently stored in the
FIFO will be continuously transmitted through the I2S_SDO pin until the FIFO becomes empty. After
I2SSTART is set to 0, new transmit data cannot be written to the FIFO.
Note: Be sure to avoid altering the I2S_DV_MCLK and I2S_DV_AUDIO_CLK registers when
I2SSTART is 1.
I
2
S FIFO Status Register (I2S_FIFO_STAT)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
I
2
S FIFO Status
Register (I2S_
FIFO_STAT)
0x30140a
(16 bits)
D15–5 –
reserved
–
–
–
0 when being read.
D4–2 FIFOSTAT
[2:0]
I
2
S FIFO state machine
FIFOSTAT[2:0]
State
0x0
R
0x7–0x6
0x5
0x4
0x3
0x2
0x1
0x0
reserved
FLUSH
EMPTY
LACK
FULL
INIT
STOP
D1
I2SFIFOFF I
2
S FIFO full flag
1 Full
0 Not full
0
R
D0
I2SFIFOEF I
2
S FIFO empty flag
1 Empty
0 Not empty
1
R
D[15:5] Reserved
D[4:2]
FIFOSTAT[2:0]: I
2
S FIFO State Machine Bits
Indicates the transmit FIFO status.