12 UART (UART3)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
12-13
TECHNICAL MANUAL (Rev. 1.0)
UART3 Ch.
n
Status and Interrupt Flag Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
UAnINTF
15–10 –
0x00
–
R
–
9
RBSY
0
H0/S0
R
8
TBSY
0
H0/S0
R
7
–
0
–
R
6
TENDIF
0
H0/S0
R/W Cleared by writing 1.
5
FEIF
0
H0/S0
R/W Cleared by writing 1 or reading the
UAnRXD register.
4
PEIF
0
H0/S0
R/W
3
OEIF
0
H0/S0
R/W Cleared by writing 1.
2
RB2FIF
0
H0/S0
R
Cleared by reading the UAnRXD reg-
ister.
1
RB1FIF
0
H0/S0
R
0
TBEIF
1
H0/S0
R
Cleared by writing to the UAnTXD
register.
Bits 15–10 Reserved
Bit 9
RBSY
This bit indicates the receiving status. (See Figure 12.5.3.1.)
1 (R):
During receiving
0 (R):
Idle
Bit 8
TBSY
This bit indicates the sending status. (See Figure 12.5.2.1.)
1 (R):
During sending
0 (R):
Idle
Bit 7
Reserved
Bit 6
TENDIF
Bit 5
FEIF
Bit 4
PEIF
Bit 3
OEIF
Bit 2
RB2FIF
Bit 1
RB1FIF
Bit 0
TBEIF
These bits indicate the UART3 interrupt cause occurrence status.
1 (R):
Cause of interrupt occurred
0 (R):
No cause of interrupt occurred
1 (W):
Clear flag
0 (W):
Ineffective
The following shows the correspondence between the bit and interrupt:
UA
n
INTF.TENDIF bit: End-of-transmission interrupt
UA
n
INTF.FEIF bit:
Framing error interrupt
UA
n
INTF.PEIF bit:
Parity error interrupt
UA
n
INTF.OEIF bit:
Overrun error interrupt
UA
n
INTF.RB2FIF bit: Receive buffer two bytes full interrupt
UA
n
INTF.RB1FIF bit: Receive buffer one byte full interrupt
UA
n
INTF.TBEIF bit: Transmit buffer empty interrupt