R01UH0823EJ0100 Rev.1.00
Page 1305 of 1823
Jul 31, 2019
RX23W Group
37. Serial Sound Interface (SSI)
Note 1. While this module is muted, low is transmitted regardless of the value of serial data, but data transmission is not stopped. Since
the number of data in the transmit FIFO decreases, write dummy data to the SSIFTDR register to prevent the generation of a
transmit underflow. When the MUEN bit is set to 1, the SSITXD0 pin immediately becomes low without synchronizing SSIWS0
pin.
Note 2. Set the SCKD and SWSD bits to the same value. Other settings are prohibited.
Note 3. Rewriting is allowed only in the idle state.
b12
Word Select Polarity
0: SSIWS0 is low for the 1st system word, high for the 2nd
system word.
1: SSIWS0 is high for the 1st system word, low for the 2nd
system word.
R/W
b13
Serial Bit Clock Polarity*
0: SSIWS0 and SSITXD0 change at the SSISCK0 falling edge
(SSIWS0 and SSIRXD0 are sampled at the SSISCK0 rising
edge).
1: SSIWS0 and SSITXD0 change at the SSISCK0 rising edge
(SSIWS0 and SSITXD0 are sampled at the SSISCK0 falling
edge).
R/W
b14
Word Select Direction*
0: SSIWS0 pin is input (slave mode).
1: SSIWS0 pin is output (master mode).
R/W
b15
Serial Bit Clock Direction*
0: SSISCK0 pin is input (slave mode).
1: SSISCK0 pin is output (master mode).
R/W
b18 to b16
System Word Length*
Set the system word length to the bit clock frequency/2 fs.
b18
b16
0 0 0: 8 bits (serial bit clock frequency = 16 fs)
0 0 1: 6 bits (serial bit clock frequency = 32 fs)
0 1 0: 24 bits (serial bit clock frequency = 48 fs)
0 1 1: 32 bits (serial bit clock frequency = 64 fs)
Settings other than above are prohibited.
R/W
b21 to b19
Data Word Length*
b21
b19
0 0 0: 8 bits
0 0 1: 16 bits
0 1 0: 18 bits
0 1 1: 20 bits
1 0 0: 22 bits
1 0 1: 24 bits
Settings other than above are prohibited.
R/W
b23, b22
Channels*
b23 b22
0 0: One channel
Settings other than above are prohibited.
R/W
b24
—
Reserved
This bit is read as 0. The write value should be 0.
R/W
b25
Idle Interrupt Enable
0: Disables an idle interrupt.
1: Enables an idle interrupt.
R/W
b26
Receive Overflow Interrupt
Enable
0: Disables a receive overflow interrupt.
1: Enables a receive overflow interrupt.
R/W
b27
Receive Underflow Interrupt
Enable
0: Disables a receive underflow interrupt.
1: Enables a receive underflow interrupt.
R/W
b28
Transmit Overflow Interrupt
Enable
0: Disables a transmit overflow interrupt.
1: Enables a transmit overflow interrupt.
R/W
b29
Transmit Underflow Interrupt
Enable
0: Disables a transmit underflow interrupt.
1: Enables a transmit underflow interrupt.
R/W
b30
Audio Clock Select*
0: AUDIO_MCLK input
1: Main clock
R/W
b31
—
Reserved
This bit is read as 0. The write value should be 0.
R/W
Bit
Symbol
Bit Name
Description
R/W