18 UNIVERSAL SERIAL INTERFACE (USI)
18-26
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
USI UART Mode Interrupt Enable Register (USI_UIE)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
USI UART Mode
Interrupt En-
able Register
(USI_UIE)
0x300441
(8 bits)
D7–3 –
reserved
–
–
–
0 when being read.
D2
UEIE
Receive error interrupt enable
1 Enable
0 Disable
0
R/W
D1
URDIE
Receive buffer full interrupt enable 1 Enable
0 Disable
0
R/W
D0
UTDIE
Transmit buffer empty int. enable
1 Enable
0 Disable
0
R/W
Note: This register is effective only in UART mode. Configure USI to UART mode before this register
can be used.
D[7:3]
Reserved
D2
UEIE: Receive Error Interrupt Enable Bit
Enables interrupt requests to the ITC when a receive error occurs.
1 (R/W): Enabled
0 (R/W): Disabled (default)
Set this bit to 1 to process receive errors using interrupts.
D1
URDIE: Receive Buffer Full Interrupt Enable Bit
Enables interrupt requests to the ITC when received data is loaded to the receive data buffer.
1 (R/W): Enabled
0 (R/W): Disabled (default)
Set this bit to 1 to read received data using interrupts.
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.
USI UART Mode Interrupt Flag Register (USI_UIF)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
USI UART Mode
Interrupt Flag
Register
(USI_UIF)
0x300442
(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 USI 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 USI status in UART mode.
1 (R):
Busy
0 (R):
Idle (default)