19 UNIVERSAL SERIAL INTERFACE WITH LCD INTERFACE (USIL)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
19-35
D0
UTDIE: Transmit Buffer Empty Interrupt Enable Bit
Enables interrupt requests to the ITC when data written to the transmit data buffer is sent to the shift
register (i.e. when data transmission begins).
1 (R/W): Enabled
0 (R/W): Disabled (default)
Set this bit to 1 to write data to the transmit data buffer using interrupts.
USIL UART Mode Interrupt Flag Register (USIL_UIF)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
USIL UART
Mode Interrupt
Flag Register
(USIL_UIF)
0x300642
(8 bits)
D7
–
reserved
–
–
–
0 when being read.
D6
URBSY
Receive busy flag
1 Busy
0 Idle
0
R
D5
UTBSY
Transmit busy flag
1 Busy
0 Idle
0
R
D4
UPEIF
Parity error flag
1 Error
0 Normal
0
R/W Reset by writing 1.
D3
USEIF
Framing error flag
1 Error
0 Normal
0
R/W
D2
UOEIF
Overrun error flag
1 Error
0 Normal
0
R/W
D1
URDIF
Receive buffer full flag
1 Full
0 Not full
0
R/W
D0
UTDIF
Transmit buffer empty flag
1 Empty
0 Not empty
0
R/W
Note: This register is effective only in UART mode. Configure USIL to UART mode before this register
can be used.
D7
Reserved
D6
URBSY: Receive Busy Flag Bit
Indicates the receive shift register status.
1 (R):
Busy
0 (R):
Idle (default)
URBSY is set to 1 when the first start bit is detected (when data reception begins) and is reset to 0 when
the data received in the shift register is loaded into the receive data buffer. Inspect URBSY to determine
whether the receiving circuit is operating or at standby.
D5
UTBSY: Transmit Busy Flag Bit
Indicates the USIL status in UART mode.
1 (R):
Busy
0 (R):
Idle (default)
UTBSY switches to 1 when transmit data is written to the transmit buffer and reverts to 0 after both the
shift register and transmit buffer become empty.
D4
UPEIF: Parity Error Flag Bit
Indicates whether a parity error has occurred or not.
1 (R):
Error occurred
0 (R):
No error (default)
1 (W):
Reset to 0
0 (W):
Ignored
UPEIF is set to 1 when a parity error occurs. At the same time a receive error interrupt request is sent to
the ITC if UEIE/USIL_UIE register is 1. Parity checking is enabled only when UPREN/USIL_UCFG
register is set to 1 and is performed when received data is transferred from the shift register to the
receive data buffer. UPEIF is reset by writing 1.
D3
USEIF: Framing Error Flag Bit
Indicates whether a framing error has occurred or not.
1 (R):
Error occurred
0 (R):
No error (default)
1 (W):
Reset to 0
0 (W):
Ignored
USEIF is set to 1 when a framing error occurs. At the same time a receive error interrupt request is sent
to the ITC if UEIE/USIL_UIE register is 1. A framing error occurs when data is received with the stop
bit set to 0. USEIF is reset by writing 1.