User Manual

APEX/APEX LT
Datasheet (Preliminary Rev 0.2) www.lsr.com Page 7 of 20
6.2 I/O pin assignments for the APEX LT module
Pin # Name Type Description
1 GROUND GND Ground
2 GROUND GND Ground
3 GROUND GND Ground
4 GROUND GND Ground
5 VDD PI Power Supply Input
6 nRESET DI Reset, active low
7 MOSI DI SPI Data, Master Out/Slave In (from Host to APEX LT)
8 MISO DO SPI Data, Master In/Slave Out (from APEX LT to Host)
9 SCLK DI SPI Clock (from Host to APEX LT)
10 VPA_EN DI APEX LT Enable, active high (see section 8)
11 nRTS DO UART RTS
12 nSSEL_INT/nCTS DI SPI Slave Select (from Host to APEX LT)/UART CTS
13 PTI_EN DO PTI Frame signal
14 PTI_DATA DO PTI Data signal
15 TXD DO UART TXD
16 nHOST_INT/RXD DO/DI Host Interrupt Signal (from APEX LT to Host) or UART RXD
17 nWAKE DI Wake Interrupt Signal (from host to APEX LT)
18 GROUND GND Ground
19 SIF_CLK DI SIF Interface clock
20 SIF_MISO DO SIF Interface master in/slave out
21 SIF_MOSI DI SIF Interface master out/slave in
22 nSIF_LOAD DI/DO SIF Interface load strobe
23 SDBG DO Spare Debug Signal
24 LINK_ACTIVITY DO Link and Activity signal
25 GROUND GND Ground
26 GROUND GND Ground
27 GROUND GND Ground
28 GROUND GND Ground
Unused I/O pins should be left unconnected and the pin state set via the Host Protocol.
DI = Digital Input PI = Power Input AI = Analog Input
DO = Digital Output GND = Ground AO = Analog Output
The APEX LT module provides a connection to the Ember Serial API over the SPI allowing the
application development to be completed on a host microprocessor of choice. In addition to
the SPI signals, two additional signals (nHOST_INT and nWAKE) provide a handshake
mechanism. The module is the slave device with all transactions initiated by the host. Please
consult the EM260 datasheet (
www.ember.com) for details on the SPI Protocol including:
• Physical Interface Configuration
• SPI Transactions
• SPI Protocol Timing Parameters & Waveforms
• Data Formatting
• SPI Commands & Responses
• Handling Resets and Power Cycling
• Transaction Examples