BS87B12A-3 Datasheet, PDF (140/224 Pages) Holtek Semiconductor Inc – Touch A/D Flash MCU with OCVP

BS87B12A-3/BS87C16A-3/BS87D20A-3
Touch A/D Flash MCU with OCVP
I²C interface Operation
The I²C serial interface is a two line interface, a serial data line, SDA, and serial clock line, SCL. As
many devices may be connected together on the same bus, their outputs are both open drain types.
For this reason it is necessary that external pull-high resistors are connected to these outputs. Note
that no chip select line exists, as each device on the I²C bus is identified by a unique address which
will be transmitted and received on the I²C bus.
When two devices communicate with each other on the bidirectional I²C bus, one is known as the
master device and one as the slave device. Both master and slave can transmit and receive data;
however, it is the master device that has overall control of the bus. For these devices, which only
operate in slave mode, there are two methods of transferring data on the I²C bus, the slave transmit
mode and the slave receive mode. The pull-high control function pin-shared with the SCL or SDA
pin is still applicable even if the I²C interface is activated and the related internal pull-up resistor
could be controlled by its corresponding pull-up control register.
Data Bus
SCL Pin
SDA Pin
Add�ess Mat�h
SIMTOEN
fSUB
Ti�e-out
Cont�ol
I²C Data Registe�
(SIMD)
SIMTOF
fSYS
De�oun�e
Ci��uit�y
SIMDEB1
&
SIMDEB0
Di�e�tion Cont�ol
HTX Bit
Data in
Shift Registe�
M
U
X
Data out
TXAK
T�ans�it/
Re�eive
Cont�ol Unit
Slave Add�ess Registe�
(SIMA)
Add�ess Add�ess Mat�h
Co�pa�ato� HAAS Bit
SIMTOF Bit
Read/W�ite Slave
SRW Bit
8-�it Data Co�plete
Dete�t Sta�t o� Stop
HCF Bit
HBB Bit
I²C Block Diagram
I²C Inte��upt
START signal
f�o� Maste�
Send slave add�ess
and R/W �it f�o� Maste�
A�knowledge
f�o� slave
Send data �yte
f�o� Maste�
A�knowledge
f�o� slave
STOP signal
f�o� Maste�
Rev. 1.20
140
December 05, 2016