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.
IDST Flag (Idle Status Flag)
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
——TUIRQTOIRQRUIRQROIRQIIRQ—————————
Value after reset:
0000001000000000
b15b14b13b12b11b10b9b8b7b6b5b4b3b2b1b0
—————————TCHNO[1:0]
TSWN
O
RCHNO[1:0]
RSWN
O
IDST
Value after reset:
0000000000010011
Bit Symbol Bit Name Description R/W
b0 IDST Idle Status Flag 0: SSI communication is in progress.
1: SSI communication is idle.
R
b1 RSWNO Receive System Word Number
Flag
Receive word number R
b3, b2 RCHNO[1:0] Receive Channel Number Flag These bits are read as 00b. R
b4 TSWNO Transmit System Word Number
Flag
Transmit word number R
b6, b5 TCHNO[1:0] 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 IIRQ Idle Interrupt Status Flag 0: Not in idle state
1: In idle state
R
b26 ROIRQ Receive Overflow Interrupt
Status Flag
0: No receive overflow has occurred.
1: A receive overflow has occurred.
R/(W)
*
1
b27 RUIRQ Receive Underflow Interrupt
Status Flag
0: No receive underflow has occurred.
1: A receive underflow has occurred.
R/(W)
*
1
b28 TOIRQ Transmit Overflow Interrupt
Status Flag
0: No transmit overflow has occurred.
1: A transmit overflow has occurred.
R/(W)
*
1
b29 TUIRQ Transmit Underflow Interrupt
Status Flag
0: No transmit underflow has occurred.
1: A transmit underflow has occurred.
R/(W)
*
1
b31, b30 — Reserved These bits are read as 0. The write value should be 0. R/W
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