19 UNIVERSAL SERIAL INTERFACE WITH LCD INTERFACE (USIL)
19-36
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
D2
UOEIF: Overrun Error Flag Bit
Indicates whether an overrun error has occurred or not.
1 (R):
Error occurred
0 (R):
No error (default)
1 (W):
Reset to 0
0 (W):
Ignored
UOEIF is set to 1 when an overrun error occurs. At the same time a receive error interrupt request is
sent to the ITC if UEIE/USIL_UIE register is 1. An overrun error occurs if the next reception is com-
pleted when URDIF is 1 and the receive data buffer (USIL_RD register) is not read (an overrun error
occurs at the time stop bit has been received). To reset UOEIF, perform USIL software reset (write 0x0
to USILMOD[2:0]/USIL_GCFG register) to initialize USIL.
D1
URDIF: Receive Buffer Full Flag Bit
Indicates the receive data buffer status.
1 (R):
Data full
0 (R):
No data (default)
1 (W):
Reset to 0
0 (W):
Ignored
URDIF is set to 1 when data received in the shift register is sent to the receive data buffer (when receiv-
ing is completed), indicating that the data can be read. At the same time a receive buffer full interrupt
request is sent to the ITC if URDIE/USIL_UIE register is 1. URDIF is reset by writing 1.
D0
UTDIF: Transmit Data Buffer Empty Flag Bit
Indicates the transmit data buffer status.
1 (R):
Empty
0 (R):
Data exists (default)
1 (W):
Reset to 0
0 (W):
Ignored
UTDIF is set to 1 when the transmit data written to the transmit data buffer is transferred to the shift
register (when transmission starts), indicating that the next transmit data can be written to. At the same
time a transmit buffer empty interrupt request is sent to the ITC if UTDIE/USIL_UIE register is 1.
UTDIF is reset by writing 1.
USIL SPI Master/Slave Mode Configuration Register (USIL_SCFG)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
USIL SPI
Master/Slave
Mode Configu-
ration Register
(USIL_SCFG)
0x300650
(8 bits)
D7–4 –
reserved
–
–
–
0 when being read.
D3
SCPHA
Clock phase select
1 Phase 1
0 Phase 0
0
R/W
D2
SCPOL
Clock polarity select
1 Active L
0 Active H
0
R/W
D1
–
reserved
–
–
–
Do not set to 1.
D0
SFSTMOD Fast mode select
1 Fast
0 Normal
0
R/W
Note: This register is effective only in SPI master and slave modes. Configure USIL to SPI master/slave
mode before this register can be used.
D[7:4]
Reserved
D3
SCPHA: Clock Phase Select Bit
Selects the SPI clock phase.
1 (R/W): Phase 1
0 (R/W): Phase 0 (default)
Set the data transfer timing together with SCPOL. (See Figure 19.8.1.)
D2
SCPOL: Clock Polarity Select Bit
Selects the SPI clock polarity.
1 (R/W): Active low
0 (R/W): Active high (default)
Set the data transfer timing together with SCPHA. (See Figure 19.8.1.)