7-Bit Slave Address Mask Register (Ismk) - Fujitsu FR60 Hardware Manual

15.2.7

7-bit Slave Address Mask Register (ISMK)

Rewrite the 7-bit slave address mask register (ISMK) while operation is stopped (EN =
0 in ICCR).
■ 7-bit Slave Address Mask Register (ISMK)
The configuration of the 7-bit slave address mask register (ISMK) is shown below.
[Bit 15] ENSB (7-bit slave address enable bit)
This bit is the 7-bit slave address enable bit.
Value
0
1
[Bits 14 to 8] 7-bit slave address mask bits
These bits mask the bits of the 7-bit slave address register (ISBA).
Value
0
1
Setting this bit enables transmission of an acknowledge to a compound 7-bit slave address. When using
this register for comparison of a 7-bit slave address, set this bit to "1". The received slave address is
overwritten to ISBA. When ASS = 1 (IBSR), the specified slave address can be determined by reading the
ISBA register.
After the I
SMK is rewritten, SMK must be set again to provide the expected operation.
Each of the SM6-0 bits of ISMK corresponds to one bit of the ISBA address. If the value of each of the
SM6-0 bit is "1", the ISBA address becomes valid; if it is "0", the ISBA address becomes invalid.
Example: If ISBA address is 0010111
The slave address is in the space from 0010100
461
15
Address : 00009A ENSB
H
R/W
Initial value→ 0
7-bit slave address disabled
7-bit slave address enabled
This bit is not used for comparison of slave addresses
This bit is used for comparison of slave addresses
2
C interface is enabled, the slave address (ISBA) is rewritten by reception operation. When
15.3 Explanation of I
14 13 12 11
SM6 SM5 SM4 SM3
R/W R/W R/W R/W
1 1 1
Function
Function
and ISMK address is 1111100
B
to 0010111 .
B B
2
C Operation
10 9 8
SM2 SM1 SM0
R/W R/W R/W
1 1 1 1
:
B