Jennic USB Programming Dongle
Reference Manual
8 © Jennic 2010 JN-RM-2056 v1.0
2.5 LED
Two LEDs are provided that are controlled by the CB0 and CB1 pins of U3 (the
FTDI232RL device). When a pin is driven low then the corresponding LED is
switched on. These LEDs can be controlled via a control register within U3, which is
accessible via the USB interface. The LEDs are expected to be used for signalling
transmit and receive activity, as indicated on the silkscreen.
LED Expected function U3 Connection
D1 TX from USB CB0
D2 RX into USB CB1
Table 1: LED Connections
2.6 Primary Connector for Programming Interface
The connector J8 supports the programming interface for the remote hardware
(i.e. the JN5148 board that is to be programmed) and employs 3.3V signals.
Pin Name Use
1 DIO6 (input) Receive UART data, to connect to UART0 TXD output from remote
JN5148, i.e. DIO6.
2 DIO7 (output) Transmit UART data, to connect to UART0 RXD input of the JN5148,
i.e. DIO7.
3 MISO (output) Control line to connect to SPIMISO of the JN5148 – used in
conjunction with RESETN to put remote JN5148 into programming
mode. It is only possible to cause this pin to go low, due to diode D5.
4 3V30 3.3V supply output from programming interface. This is capable of
providing up to 40mA.
5 RESETN (output)
Control line to connect to RESETN of the JN5148 - used in
conjunction with MISO to put remote JN5148 into programming mode.
Also used to reset the JN5148 after a programming cycle. It is only
possible to cause this pin to go low, due to the diode D4.
6 GND Ground
Table 2: Pinout of J8 Connector
The connector takes the physical form of 6 plated vias at a 1.27-mm pitch, suitable
for direct soldering of a ribbon cable as shown in Figure 1. Pin 1 is identified by the
square pad in the Reference Design material. Ideally, the target application board
will have a 6-pin header specifically designed for this programming interface.
