User Manual

Table Of Contents

Jennic

Module

Signal Function Alternative Function

31 SIF_D Serial Interface data / Intelligent peripheral data

General Purpose Digital I/O DIO15

32 DIO 16 Intelligent peripheral device select General Purpose Digital I/O

33 CTS1 UART1 Clear To Send (input) General Purpose Digital I/O DIO17

34 RTS1 UART1 Request To Send (output) General Purpose Digital I/O DIO18

35 TXD1 UART1 Transmit Data (output) General Purpose Digital I/O DIO19

36 RXD1 UART1 Receive Data (input) General Purpose Digital I/O DIO20

37 DNC

38 DNC

Do Not Connect

39 ADC1 Analogue to Digital input

40 ADC2 Analogue to Digital input

41 ADC3 Analogue to Digital input

*: These two pins are not connected for High power modules

4.2. Pin Descriptions

All pins behave as described in the JN5121 datasheet [2], with the exception of the following:

4.3. Power Supplies

A single power supply pin, VDD is provided. Separate analogue (VSSA) and digital (GND) grounds are provided.

These should be connected together at the module pins.

4.4. SPI Memory Connections

SPISWP is a write protect pin for the serial flash memory. This should be held low to inhibit writes to the flash device.

SPISSZ is connected to SPI Slave Select 0 on the JN5121.

SPISSM is connected to the Slave Select pin on the memory.

This configuration allows the flash memory device to be programmed using an external programmer if required. The

JN5121 should be held in reset by taking RESETN low. The memory can then be programmed over the UART by

using the programming mode described in

JN-UG-3007 Flash Loader User Guide [5]. Alternatively, the memory can

be programmed by connecting a SPI programmer to SPISSM, SPICLK, and SPIMISO and directly loading the code

into the memory.

For normal operation of the module, SPISSZ should be connected to SPISSM.