16 I
2
C (I2C)
16-22
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
I2C Ch.
n
Status and Interrupt Flag Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
I2C_nINTF
15–13 –
0x0
–
R
–
12 SDALOW
0
H0
R
11 SCLLOW
0
H0
R
10 BSY
0
H0/S0
R
9
TR
0
H0
R
8
–
0
–
R
7
BYTEENDIF
0
H0/S0
R/W Cleared by writing 1.
6
GCIF
0
H0/S0
R/W
5
NACKIF
0
H0/S0
R/W
4
STOPIF
0
H0/S0
R/W
3
STARTIF
0
H0/S0
R/W
2
ERRIF
0
H0/S0
R/W
1
RBFIF
0
H0/S0
R
Cleared by reading the I2C_nRXD
register.
0
TBEIF
0
H0/S0
R
Cleared by writing to the I2C_nTXD
register.
Bits 15–13 Reserved
Bit 12
SDALOW
This bit indicates that SDA is set to low level.
1 (R):
SDA = Low level
0 (R):
SDA = High level
Bit 11
SCLLOW
This bit indicates that SCL is set to low level.
1 (R):
SCL = Low level
0 (R):
SCL = High level
Bit 10
BSY
This bit indicates that the I
2
C bus is placed into busy status.
1 (R):
I
2
C bus busy
0 (R):
I
2
C bus free
Bit 9
TR
This bit indicates whether the I2C is set in transmission mode or not.
1 (R):
Transmission mode
0 (R):
Reception mode
Bit 8
Reserved
Bit 7
BYTEENDIF
Bit 6
GCIF
Bit 5
NACKIF
Bit 4
STOPIF
Bit 3
STARTIF
Bit 2
ERRIF
Bit 1
RBFIF
Bit 0
TBEIF
These bits indicate the I2C interrupt cause occurrence status.
1 (R):
Cause of interrupt occurred
0 (R):
No cause of interrupt occurred
1 (W):
Clear flag
0 (W):
Ineffective