Rev. 1.00
80
March 24, 2020
Rev. 1.00
81
March 24, 2020
BS83A04C
4-Key Enhanced Touch I/O Flash MCU
BS83A04C
4-Key Enhanced Touch I/O Flash MCU
START signal
from Master
Send slave address
and R/W bit from Master
Acknowledge
from slave
Send data byte
from Master
Acknowledge
from slave
STOP signal
from Master
I
2
C Interface Operation
The IICDEB1 and IICDEB0 bits determine the debounce time of the I
2
C interface. This uses the
internal clock to in effect add a debounce time to the external clock to reduce the possibility of
glitches on the clock line causing erroneous operation. The debounce time, if selected, can be
chosen to be either 2 or 4 system clocks. To achieve the required I
2
C data transfer speed, there
exists a relationship between the system clock, f
SYS
, and the I
2
C debounce time. For either the I
2
C
Standard or Fast mode operation, users must take care of the selected system clock frequency and
the configured debounce time to match the criterion shown in the following table.
I
2
C Debounce Time Selection
I
2
C Standard Mode (100kHz)
I
2
C Fast Mode (400kHz)
No Debounce
f
SYS
> 2MHz
f
SYS
> 5MHz
2 system clock debounce
f
SYS
> 4MHz
f
SYS
> 10MHz
4 system clock debounce
f
SYS
> 8MHz
f
SYS
> 20MHz
I
2
C Minimum f
SYS
Frequency Requirement
I
2
C Registers
There are three control registers associated with the I
2
C bus, IICC0, IICC1 and IICTOC, one address
register IICA and one data register, IICD.
Register
Name
Bit
7
6
5
4
3
2
1
0
IICC0
—
—
—
—
IICDEB1 IICDEB0
IICEN
—
IICC1
HCF
HAAS
HBB
HTX
TXAK
SRW
IAMWU
RXAK
IICD
D7
D6
D5
D4
D3
D2
D1
D0
IICA
IICA6
IICA5
IICA4
IICA3
IICA2
IICA1
IICA0
—
IICTOC IICTOEN
IICTOF
IICTOS5 IICTOS4 IICTOS3 IICTOS2 IICTOS1 IICTOS0
I
2
C Register List
I
2
C Data Register
The IICD register is used to store the data being transmitted and received. Before the device writes
data to the I
2
C bus, the actual data to be transmitted must be placed in the IICD register. After the
data is received from the I
2
C bus, the device can read it from the IICD register. Any transmission or
reception of data from the I
2
C bus must be made via the IICD register.