Fujitsu FR81S Manuel D’Utilisation
CHAPTER 40: MULTI-FUNCTION SERIAL INTERFACE
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : MULTI-FUNCTION SERIAL INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
135
4.5.8.
7-bit Slave Address Mask Register: ISMK
7-bit slave address mask register (ISMK) compares and configures bits of slave address.
ISMKn(n=3 to 8, 10, 11) : Address Base addr + 1E
H
(Access: Byte, Half-word,
Word)
7
6
5
4
3
2
1
0
bit
EN
SM6
SM5
SM4
SM3
SM2
SM1
SM0
0
1
1
1
1
1
1
1
Initial value
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Attribute
[bit7] EN: I
2
C interface enable bit
This bit enables/disables I
2
C interface operation.
If this bit is set to "0", I
2
C interface becomes disabled.
If this bit is set to "1", I
2
C interface becomes enabled.
EN
I
2
C-UART operation enable bit
0
Disabled
1
Enabled
Notes:
⋅
When the BER bit of the IBSR register is set to "1", this bit will not be cleared to "0".
⋅
Configure the baud rate generator when this bit is "0".
⋅
When this bit is "0", configure 7-bit slave address and 7-bit slave mask register.
⋅
If the I
2
C interface is disabled (EN="0"), transmission/reception become disabled immediately.
⋅
When you disable the I
2
C interface operation after generating a stop condition by writing "0" to the
IBCR:MSS bit, disable it (EN="0") after checking for the generation of the stop condition.
⋅
Setting "0" to the EN bit during transmission could generate SDA/SCL pulse on the I
2
C bus.
[bit6 to bit0] SM6-0: Slave address mask bits
These bits configure whether to exclude the 7-bit slave address and received address as the comparison
targets.
If these bits are set to "0": treat as matched
If these bits are set to "1": compare
SM6-0
7-bit slave address mask bits
0
Bits not compared
1
Bits compared
Note:
Configure this register when the EN bit is "0".
MB91520 Series
MN705-00010-1v0-E
1448