14 I
2
C (I2C)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
14-21
TECHNICAL MANUAL (Rev. 1.0)
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
The following shows the correspondence between the bit and interrupt:
I2C
n
INTF.BYTEENDIF bit: End of transfer interrupt
I2C
n
INTF.GCIF bit:
General call address reception interrupt
I2C
n
INTF.NACKIF bit:
NACK reception interrupt
I2C
n
INTF.STOPIF bit:
STOP condition interrupt
I2C
n
INTF.STARTIF bit:
START condition interrupt
I2C
n
INTF.ERRIF bit:
Error detection interrupt
I2C
n
INTF.RBFIF bit:
Receive buffer full interrupt
I2C
n
INTF.TBEIF bit:
Transmit buffer empty interrupt
I2C Ch.
n
Interrupt Enable Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
I2CnINTE
15–8 –
0x00
–
R
–
7
BYTEENDIE
0
H0
R/W
6
GCIE
0
H0
R/W
5
NACKIE
0
H0
R/W
4
STOPIE
0
H0
R/W
3
STARTIE
0
H0
R/W
2
ERRIE
0
H0
R/W
1
RBFIE
0
H0
R/W
0
TBEIE
0
H0
R/W
Bits 15–8 Reserved