ZTE Corporation ZM8300G Manual Do Utilizador
ZTE ZM8300G Module Hardware User Manual
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3.6.4
I
2
C Bus
I
2
C is a two-wire bus used for communication between ICs and supports all IC processes
(NMOS, CMOS, and bipolar). The two signal lines, namely, the serial data (SDA) line and the
serial clock (SCL) line, transfer information between connected devices. Each device (a
microcontroller, memory, LCD driver, audio DAC, or keyboard interface) is identified by a
unique address and used as a transmitter or a receiver, depending on the provided functions.
The I
2
C interface has the following characteristics:
1) The two-wire bus is used for communication between chips.
2) Supports all ICs on the I
2
C bus. Each device has a unique address and can be used as a
transmitter or a receiver.
3) Supports external functions, including cameras, microcontrollers, FM radio chips, LCD
drivers, audio DACs, and keyboard interfaces.
4) An I
2
C controller provides an interface between advanced high-performance buses
(AHBs) and an industry-standard I
2
C serial bus to handle the I
2
C protocol and release chip
processors and interfaces, so that the chip processors and interfaces can handle other
services.
5) The I
2
C interface works in standard mode (100 kbit/s) or high-speed mode (400 kbit/s).
The operating frequency of the ZM8300G I
2
C interface reaches 400 kHz. When the ZM8300G
I
2
C interface works only in master mode, the operating frequency may reach 1 MHz.
6) When using the I
2
C bus, configure the corresponding BLSP pin as an open drain output
GPIO. In this case, an external device needs to use VIO to provide pull-up. The group of I
2
C
buses provided by the ZM8300G module (BLSPA_2 and BLSPA_3) already has pull-up. To
configure other I
2
C buses, a customer needs to add an external pull-up. Figure 3-12 illustrates
an I
2
C reference circuit.