Data Sheet

LC840PA
Datasheet
https://www.lairdconnect.com
34
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Signal Name
Pin No
I/O
Comments
SWDIO
1
I/O
Internal pull-up resistor
SWDCLK
3
I
Internal pull-down resistor
The Laird development board incorporates an on-board JTAG J-link programmer for this purpose. There is also the following
JTAG connector which allows on-board JTAG J-link programmer signals to be routed off the development board. The only
requirement is that you should use the following JTAG connector on the host PCB.
The JTAG connector MPN is as follows:
Reference
Part
Description and MPN (Manufacturers Part Number)
JP1
FTSH-105
Header, 1.27mm, SMD, 10-way, FTSH-105-01-L-DV Samtech
Note: Reference on the BL654PAdevelopment board schematic (Figure 7) shows the DVK development schematic wiring
only for the JTAG connector and the BL654PA (LC840PA) module JTAG pins.
Figure 7:BL654PA development board schematic
Note: The BL654PA development board allows Laird on-board JTAG J-link programmer signals to be routed off the
development board by from connector JP1
JTAG is require because Nordic SDK application and the ProFLEX application can only be loaded using the JTAG (smartBASIC
firmware can be loaded using JTAG as well as over the UART). We recommend that you use JTAG (2-wire SWD interface) to
handle future LC840PA module firmware upgrades. You must wire out the JTAG (2-wire SWD interface) on your host design
(see Figure 7, where the following four lines should be wired out – SWDIO, SWDCLK, GND and VCC). smartBASIC firmware
upgrades can still be performed over the LC840PA UART interface, but this is slower than using the LC840PA JTAG (2-wire
SWD interface) – (60 seconds using UART vs. 10 seconds when using JTAG).
SWO (SIO_32) is a Trace output (called SWO, Serial Wire Output) and is not necessary for programming LC840PA over the
SWD interface.
nRESET_BLE is not necessary for programming LC840PA over the SWD interface.
5.13 LC840PA Wakeup
5.13.1 Waking Up LC840PA from Host
In Bluetooth LE mode, you may configure the LC840PA’s wakeup pins via smartBASIC to do any of the following:
▪ Wake up when signal is low
▪ Wake up when signal is high
▪ Wake up when signal changes
Refer to the smartBASIC user guide for details. You can access this guide from the Laird BL654PA product page.
When running the ProFLEX firmware, wake the LC840PA from the host using the WAKE pin. The pin is active low with internal
pull-up. A pulse of 20uS or greater will wake the module when in sleep mode.
GND
SWDIO_EXT
SWDCLK_EXT
JP1
PIN HEADER,1.27mm 2X5P
1 2
3 4
5 6
7 8
9 10
nRESET_EXT
SWO_EXT
VDD_VSRC_nRF