JN516X Datasheet, PDF (49/94 Pages) NXP Semiconductors – IEEE802.15.4 Wireless Microcontroller

15 Two-Wire Serial Interface (I²C)
The JN516x includes industry standard I²C two-wire synchronous Serial Interface operates as a Master (MSIF) or
Slave (SSIF) that provides a simple and efficient method of data exchange between devices. The system uses a
serial data line (SIF_D) and a serial clock line (SIF_CLK) to perform bi-directional data transfers and includes the
following features:
Common to both master and slave:
• Compatible with both I²C and SMbus peripherals
• Support for 7 and 10-bit addressing modes
• Optional pulse suppression on signal inputs (60ns guaranteed, 125ns typical)
Master only:
• Multi-master operation
• Software programmable clock frequency
• Clock stretching and wait state generation
• Software programmable acknowledge bit
• Interrupt or bit-polling driven byte-by-byte data-transfers
• Bus busy detection
Slave only:
• Programmable slave address
• Simple byte level transfer protocol
• Write data flow control with optional clock stretching or acknowledge mechanism
• Read data preloaded or provided as required
The Serial Interface is accessed, depending upon the configuration, DIO14 and DIO15 or DIO16 and DIO17. This is
enabled under software control. The following table details which DIO are used for the Serial Interface depending
upon the configuration.
Signal
DIO Assignment
Standard pins Alternative pins
SIF_CLK
DIO14
DIO16
SIF_D
DIO15
DIO17
Table 7: Two-Wire Serial Interface IO
15.1 Connecting Devices
The clock and data lines, SIF_D and SIF_CLK, are alternate functions of DIO15 and DIO14 respectively. The serial
interface function of these pins is selected when the interface is enabled. They are both bi-directional lines,
connected internally to the positive supply voltage via weak (50kΩ) programmable pull-up resistors. However, it is
recommended that external 4.7kΩ pull-ups be used for reliable operation at high bus speeds, as shown in Figure 34.
When the bus is free, both lines are HIGH. The output stages of devices connected to the bus must have an open-
drain or open-collector in order to perform the wired-AND function. The number of devices connected to the bus is
solely dependent on the bus capacitance limit of 400pF.
As this is an optional interface with two alternate positions, the DIO cells have not been customised for I²C operation.
In particular, note that there are ESD diodes to the nominal 3 volt supply (VDD2) from the SIF_CLK and SIF_D pins.
Therefore, if the VDD supply is removed from the JN5168 and this then discharges to ground, a path would exist that
could pull down the bus lines (see 2.2.6).
© NXP Laboratories UK 2013
JN-DS-JN516x v1.1 Production
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