MAX32600 User’s Guide
Communication Peripherals
7.1 I²C
When the R/W bit is set to 1, the hardware address of the master is written in the second byte.
The General Call Address has no effect on this interface.
START Byte
The START byte is used to initiate communication with slow devices (i.e., one reliant on software polling). The START byte has no effect on this interface.
If two or more slaves are addressed at the same time, only the slave that has the smallest address (described in decimal figures), can exchange data with the master.
Communication with the other slaves is cut off.
Clock Synchronization
The I
2
C protocol accepts multiple masters on the bus. This is the reason why synchronization between the masters’ clocks is compulsory. Clock synchronization is
performed using the wired-AND connection of SCL.
Bus Arbitration
When the I
2
C bus is free, the two masters can initiate communication; only one master can make a valid transmission and the other must switch to slave mode. Each
master compares the data sent to the SDA line. If the data is different, the master with SDA high state output will switch off its SDA data output. Arbitration occurs
until only one master remains.
Master Interrupt
The
MAX32600
I
2
C Controller contains multiple interrupt sources that are combined into one interrupt request signal to the processor. The source of the interrupt is
determined by which bits are set in the
register.
It is recommended to acknowledge an interrupt before enabling it (unmask operation) to avoid a previous event triggering.
7.1.6
Peripheral Clock Selection and Clock Gating
To initialize the I
2
C master ports, the system clock source and divider must first be configured. Divider selection is dependent on many variables, including: the
targeted bus-speed, the system clock frequency, and the dividers of both the system clock frequency and the I
2
C peripheral clock (PCLK). The register field
AN_CLK_CTRL_6_I2CM.i2cm_clk_scale
enables the system clock to the I
2
C master ports and sets the system clock frequency divider. This is a 4-bit field.
Peripheral Clock Selection
Rev.1.3 April 2015
Maxim Integrated
Page 226
Содержание MAX32600
Страница 1: ...MAX32600 User s Guide April 2015...