R01UH0823EJ0100 Rev.1.00
Page 1308 of 1823
Jul 31, 2019
RX23W Group
37. Serial Sound Interface (SSI)
37.2.2
Status Register (SSISR)
Note 1. Writing 0 after confirming the flag to be 1 clears the flag. To clear flags, write 0 only to the flags to be cleared; write 1 to the other
flags. Do not write 0 to a status flag indicating 0.
This status flag indicates that the SSI is in idle state where communication is stopped.
This flag is set to 0 when communication starts after the SSICR.TEN bit or SSICR.REN bit is set to 1. Also, this flag is
set to 1 if both the TEN and REN bits are set to 0 and system word communication is completed.
If the external device stops inputting the serial bit clock before communication is completed, this flag is not set to 1.
RSWNO Flag (Receive System Word Number Flag)
The initial value of this flag is 1, and its value is inverted when the data is transferred from the receive shift register to the
SSIFRDR register.
This flag is initialized to 1 when the SSICR.REN bit value is changed from 0 to 1.
When the data word length specified by the SSICR.DWL[2:0] bits is 18 bits or more, this flag indicates which system
word the data in the SSIFRDR register represents.
Address(es): SSI0.SSISR 0008 A504h
b31
b30
b29
b28
b27
b26
b25
b24
b23
b22
b21
b20
b19
b18
b17
b16
—
—
TUIRQ TOIRQ RUIRQ ROIRQ
IIRQ
—
—
—
—
—
—
—
—
—
Value after reset:
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
—
—
—
—
—
—
—
—
—
TCHNO[1:0]
TSWN
O
RCHNO[1:0]
RSWN
O
IDST
Value after reset:
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
1
Bit
Symbol
Bit Name
Description
R/W
b0
Idle Status Flag
0: SSI communication is in progress.
1: SSI communication is idle.
R
b1
Receive System Word Number
Flag
Receive word number
R
b3, b2
Receive Channel Number Flag
These bits are read as 00b.
R
b4
Transmit System Word Number
Flag
Transmit word number
R
b6, b5
Transmit Channel Number Flag
These bits are read as 00b.
R
b24 to b7
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b25
Idle Interrupt Status Flag
0: Not in idle state
1: In idle state
R
b26
Receive Overflow Interrupt
Status Flag
0: No receive overflow has occurred.
1: A receive overflow has occurred.
R/(W)
*
b27
Receive Underflow Interrupt
Status Flag
0: No receive underflow has occurred.
1: A receive underflow has occurred.
R/(W)
*
b28
Transmit Overflow Interrupt
Status Flag
0: No transmit overflow has occurred.
1: A transmit overflow has occurred.
R/(W)
*
b29
Transmit Underflow Interrupt
Status Flag
0: No transmit underflow has occurred.
1: A transmit underflow has occurred.
R/(W)
*
b31, b30
—
Reserved
These bits are read as 0. The write value should be 0.
R/W